Operation Jatkosota

Continuation War

The 'Jatkosota' was the Finnish war against the USSR as the 'Continuation War' of the 'Talvisota' (Winter War) (25 June 1941/19 September 1944).

As such, this was therefore the second of the two wars fought between Finland and the USSR as part of World War II. At the time of the war, the Finns adopted the name 'Jatkosota' to emphasise the war’s relationship to the 'Talvisota', while the USSR saw the war as part of its struggle against Nazi Germany and its allies the Eastern Front campaign of the 'Great Patriotic War', and Germany regarded its operations in the region as part of its overall war efforts on the Eastern Front, and provided Finland with significant matériel support as well as military co-operation.

It is worth noting that Finland and Germany were not treaty bound to each other, and Finland was therefore not a German ally but rather a co-belligerent against the USSR.

Limited fighting between Finnish and Soviet forces began on 22 June, the day of which Germany launched its 'Barbarossa' invasion of the USSR, but open warfare began with a Soviet air offensive on 25 June. Finnish land operations then retook the areas of the Karelian isthmus and Ladoga Karelia which Finland had been compelled to cede to the USSR at the end of the 'Talvisota', and seized East Karelia by September 1941. On the Karelian isthmus, the Finns ended their offensive 18.5 miles (30 km) from Leningrad along the pre-World War II Russo-Finnish frontier. Finnish forces played no direct part in the siege of Leningrad, instead being content to hold their pre-World War II territory on the Karelian isthmus for some 30 months. In 1944 Soviet aircraft made raids on Helsinki and other major Finnish cities, and in the summer of the same year the Soviet 'Vyborg-Petrozavodsk Offensive Operation', 'Vyborg Offensive Operation' and 'Svir-Petrozavodsk Offensive Operation' drove the Finns from most of their gains before being halted in July and August 1944. A ceasefire ended hostilities on 5 September, and was followed by the Moscow armistice on 19 September. The 1947 Paris treaty concluded the war formally, Finland ceding Petsamo to the Soviets, leasing Porkkala to them, and paying US $226.5 million in reparations.

The Moscow Peace Treaty was signed on 12 March 1940 and ended the 'Talvisota' and cost Finland some 9.1% of its national territory and 13% of its economic capacity. Up to the time of the 'Talvisota', Finland had based its foreign policy on a series of multi-lateral guarantees of support from the League of Nations and Nordic countries, and was thus considered a failure. Finnish public opinion desired the reconquest of Finnish Karelia. The Finnish government declared the country’s defence to be its first priority, and military expenditures rose to nearly half of government spending, and Finland either bought or received as donations considerable matériel immediately after the 'Talvisota' to supplement that it had gained during the 'Talvisota'.

On Finland’s southern coast the USSR had acquired a military base in Hanko west of the capital, Helsinki, and this was garrisoned by more than 30,000 Soviet military personnel. Finland also had to resettle some 420,000 evacuees from the the territories it had lost, and to ensure the provision of adequate food supplies it was necessary to clear new land for the evacuees to cultivate. The Finnish government wished to preserve the spirit of national unanimity that had been evident during the 'Talvisota', so the celebration of the White victory over the Reds in the Finnish civil war (January/May 1918) was ended.

Relations between Finland and the USSR remained strained despite, or probably because of, the signature of the one-sided peace treaty, and there were also several disputes about the implementation of the treaty’s conditions. Finland sought security against further Soviet territorial ambitions and proposed mutual defence agreements with Norway and Sweden, but these initiatives were quashed by Moscow.

After the 'Talvisota', Germany was unpopular in Finland as it was considered an ally of the USSR, but the Finnish government nonetheless began to restore practical diplomatic relations with Germany. Finland continued its western-aligned policy and negotiated a war trade agreement with the UK, but the agreement was renounced after Germany’s 'Weserübung' invasion of Denmark and Norway on 9 April 1940, when the UK cut all trade and traffic communications with Scandinavia. With the fall of France in June 1940, a continued policy of western alignment was seem as an impossible option in Finnish foreign policy. On 15/16 June the USSR occupied Estonia, Latvia and Lithuania on the east coast of the Baltic Sea and installed puppet regimes, but within two months had annexed all three of these states s Soviet republics.

By the middle of 1940, therefore, the two remaining northern democracies, Finland and Sweden, had been encircled by the totalitarian states of Germany and the USSR. On 23 June, a short time after the Soviets began to occupy the Baltic states, Vyacheslav Molotov, the Soviet foreign minister, contacted the Finns to demand a Soviet licence for the nickel mines in Petsamo, or alternately the establishment of a joint Soviet-Finnish company to operate them. The licence to mine the deposit had earlier been granted to a British/Canadian company, and the proposition was rejected. In the following month, the Soviets demanded that Finland destroy the fortifications built in the Åland islands and give the Soviets the right to use Finnish railways to transport troops to the new Soviet base at Hanko. The Finns very reluctantly agreed to these demands. On 24 July, Molotov accused the Finnish government of persecuting the so-called Society for Peace and Friendship between Finland and USSR, a pro-communist group, and soon after this he publicly gave this group Soviet support. A Soviet front, the society organised demonstrations, some of which turned into riots.

On 31 July Adolf Hitler gave the order for the German military command to the start the planning of an invasion of the USSR. This meant that Germany had to reassess its position in relation to Finland and Romania on the northern and southern flanks of the planned undertaking. Up to this time Germany had rejected Finnish attempts to buy weapons, but in August the Germans allowed the secret sale of war matériel to Finland. German and Finnish military authorities reached agreement on 12 September, and an official exchange of diplomatic notes followed on 22 September. At the same time, the Finns granted permission for German troops to transit through Finland; a similar agreement was reached by Germany with Sweden.

In practice, this meant Germany had redrawn the northern border of German and Soviet spheres of influence. As a result, Molotov visited Berlin on 12/13 November to demand both the German withdrawal of troops from Finland and the end of German acquiescence to Finnish anti-Soviet sentiments. He also reminded the Germans of the 1939 Soviet-German non-aggression pact. When asked by Hitler how the USSR planned to settle the 'Finnish question', Molotov responded that this would be achieved in the same manner that had been employed in Bessarabia (seized from Romania in 1940) and the Baltic states. Hitler rejected this.

During December the USSR, Germany and the UK all expressed opinions about the suitability of the Finnish presidential candidates. Risto Ryti was the only candidate to whom none of the external powers had any objection, and he was elected on 19 December. In January 1941 the USSR demanded control of the Petsamo mining area but, as it by then had a rebuilt its armed forces and had German support, Finland rejected this.

On 18 December 1940 Hitler had officially approved 'Barbarossa', and expected both Finland and Romania to join the German campaign. Two days earlier, the ostensibly retired Kenraalimajuri Paavo Talvela had met Generaloberst Franz Halder, chief-of-staff of the Oberkommando des Heeres, and, two days later, Reichsmarschall Hermann Göring. This was the first time the Germans advised the Finns, in carefully couched diplomatic terms, that they were preparing for a war with the USSR. The outline of the plan was revealed to the Finns in January 1941, and regular contacts between Finnish and German military leaders started in the following month.

Late in the spring of 1941 the USSR made a number of goodwill gestures in an effort to dissuade Finland from allowing itself to fall completely under German influence. These gestures included the replacement of Ivan Zotov, the current ambassador, by the more flexible Pavel Orlov, and an announcement that the USSR no longer opposed a rapprochement between Finland and Sweden. However, these conciliatory measures did not have any effect on Finnish policy.

On 20 May, the Germans invited a number of Finnish officers to Germany to discuss co-ordination of Finnish operations with 'Barbarossa'. The participants met on 25/28 May in Salzburg and Berlin, and continued their meeting in Helsinki on 3/6 June. They agreed upon the arrival in Finland of German troops, Finnish mobilisation, and a general division of operations. They also agreed that the Finnish army would start mobilisation on 15 June, but the Germans did not reveal their launch date for 'Barbarossa'. The Finnish decisions were made by a small group of political and military leaders, and the rest of the government was kept largely uninformed. In fact, the government was not informed until 9 June that the country would start mobilisation of reservists as a result of tensions between Germany and the USSR.

The Germans took responsibility for the 310-mile (500-km) length of the front in northern Finland (Finnish Lapland). With a strength of 475,000 men, the Finnish army was now much stronger than it had been during the 'Talvisota', and had responsibility for the rest of the Finnish front. The Finnish artillery arm was also relatively strong, but on the debit side of the equation there was only one tank battalion, and motor transport was in short supply. The Finns also had the advantage of local air superiority.

At the beginning of the 'Jatkosota', the USSR had 18 divisions along the front with Finland, which was served by 15 Finnish and four German divisions, and the Soviets had also sensibly appreciated that it needed its best formations and most modern matériel on the main front against Germany. While German troops moved onto the offensive against the USSR on 22 June, they did not do so from Finland, though German minelayers which had been lurking on the Archipelago Sea (mouth of the Gulf of Bothnia between south-west Finland and Sweden) laid two large minefields across the mouth of the Gulf of Finland in the late hours of 21 June. Later in the same night, German bombers flew along the Gulf of Finland to Leningrad to mine the city’s harbour and the lower reaches of the Neva river. On their return trip the bombers landed for refuelling on the Finnish airfield in Utti.

In the early hours of 22 June, Finnish forces launched 'Kilpapurjehdus' and reoccupied the demilitarised Åland islands: an international treaty on the status of the islands allowed Finland to do so should an attack be threatened. The operation was co-ordinated with the start of 'Barbarossa', and the members of the Soviet consulate in the islands were detained.

On 21 June Finnish formations and units had begun to congregate along the border , and were deployed on the defensive. Finland mobilised 16 infantry divisions, one cavalry brigade, and two Jäger brigades, which were all standard infantry brigades, except for an armoured battalion in Eversti Ruben Lagus’s (on 11/25 July Everstiluutnantti Väinö Merikallio’s) 1st Jägerprikaati (light brigade). Independent battalions were mostly formed from border guard units and used primarily for reconnaissance.

Soviet military plans estimated that Finland would be able to mobilise only 10 infantry divisions, as it had done in the 'Talvisota', but failed to take into account the matériel Finland had received in the inter-war period and its expanded training of all available men.

Two German mountain divisions were stationed at Petsam in the form of General Eduard Dietl’s Gebirgskorps 'Norwegen' with Generalmajor Ernst Schlemmer’s 2nd Gebirgsdivision and Generalleutnant Hans Kreysing’s 3rd Gebirgsdivision, and two German infantry divisions at Salla in the form of General Hans Feige’s Höheres Kommando zbV XXXVI (soon to become the XXXVI Gebirgskorps) with Generalleutnant Erwin Engelbrecht’s 163rd Division and Generalleutnant Kurt Dittmar’s 169th Division.

On the morning of 22 June, the Gebirgskorps 'Norwegen' started to advance from northern Norway toward Petsamo, though Finland did not allow direct German attacks from its soil into the USSR. On the same day, another German infantry division was moved from Oslo to the Ladoga Karelia front.

The southern part of Finnish Lapland, under the command of Generaloberst Nikolaus von Falkenhorst’s Armee 'Norwegen', was the responsibility of Kenraalimajuri Hjalmar Siilasvuo’s Finnish III Armeijakunta (army corps). To the south of the Armee 'Norwegen', the rest of Finland south to the Gulf of Finland was entrusted to Kenraaliluutnantti Erik Heinrichs’s Karjalan Armeija (Army of Karelia), whose four corps were, from north to south, Talvela’s VI Armeijakunta and Kenraalimajuri Woldemar Hägglund’s VII Armeijakunta with some six divisions between them, and Kenraalimajuri Taavetti Laatikainen’s II Armeijakunta and Kenraaliluutnantti Karl Lennart Oesch’s IV Armeijakunta with some eight divisions between them. The overall commander of the Finnish and German forces was Sotamarsalkka Carl Gustav Emil Mannerheim.

On the other side of the front, the Soviet forces were deployed in the three armies of General Leytenant Markian M. Popov’s North Front: from north to south these were General Leytenant Valerian A. Frolov’s 14th Army (two divisions of the XLII Corps) responsible for the defence of the USSR in the area to the north of Belomorsk on the south-west coast of the White Sea, General Leytenant Fillip D. Gorelenko’s 7th Army (four divisions) covering Ladoga Karelia, and General Leytenant Piotr S. Pshennikov’s 23rd Army (six divisions of the X, XIX and L Corps) holding the Karelian isthmus and the north-western approaches to Leningrad. The Soviets also deployed some 40 battalions of a number of independent regiments as well as several fortress units. Leningrad itself was garrisoned by three infantry divisions and one mechanised corps.

As the initial devastating German onslaught against the Soviet air forces had not affected air units located near Finland, the Soviets deployed 700 aircraft as well as a number of naval air force machines against 300 Finnish aircraft.

On the morning of 25 June, the Soviet air forces launched an attack by 460 bombers and fighters against 19 Finnish airfields, but inaccurate intelligence and poor bombing skills meant that several of these raids hit Finnish cities or towns, in which there was considerable destruction. The Soviets lost 23 bombers, while the Finns lost no aircraft. However, the Soviet air offensive provided the Finnish government the opportunity to claim that the country had become the target of a new assault, and the Finnish parliament approved the 'defensive war' as a fait accompli. The USSR claimed that the air offensive had been directed against German targets, especially airfields, in Finland. At the same time Soviet artillery in the base at Hanko started to shell Finnish targets, and a minor Soviet infantry attack was launched over the border in the Parikkala area of southern Karelia.

As the USSR was struggling and failing, right from the start of 'Barbarossa', to contain the German eastward invasion, the Soviet high command had to call all available units to the rapidly deteriorating front line, and as a result the initial Soviet air offensive against Finland could not be followed by a supporting land offensive on the scale originally planned. Moreover, the 237th Division and the X Mechanised Corps (less its 198th Motorised Division) were withdrawn from Ladoga Karelia, which is the area to the north of Lake Ladoga, thereby stripping most of the reserves from the Soviet defence’s remaining strength.

In Ladoga Karelia, the Finns were initially deployed defensively, but on 29 June Mannerheim activated Heinrichs’s Karjalan Armeija and ordered preparation of an offensive into Ladoga Karelia. The Karjalan Armeija comprised the VI Armeijakunta (Eversti Eino Koskimies’s 5th Divisioona (division) and Eversti Kaarlo Heiskanen’s 11th Divisioona), the VII Armeijakunta (Eversti Antero Svensson’s 7th Divisioona and Eversti Esa Hannuksela’s 19th Divisioona) and Kenraalimajuri Woldemar Oinonen’s 'O' Ryhmä (group) (Eversti Gustaf Ehrnrooth’s Ratsuväkiprikaati (cavalry brigade), Lagus’s 1st Jääkäriprikaati and Eversti Viktor Sundman’s 2nd Jääkäriprikaati). On their later arrival into the area, Eversti Paavo Paalu’s 1st Divisioona and two regiments of the German 163rd Division were added to the Karjalan Armeija.

Opposing these Finnish forces was the 7th Army with the 168th Division near Sortavala and the 71st Division to the north of Jänisjärvi, and the Soviets had prepared field fortifications along the border across Sortavala and at the important crossroads at Värtsilä and Korpiselkä.

The Finnish offensive started on 9 July. The task of breaking through the Soviet defences was given to the VI Armeijakunta under Talvela, who had drawn in as much artillery as possible from other units of the Karjalan Armeija and the 1st Jääkäriprikaati of the 'O' Ryhmä. With strong artillery support he unleashed the 5th Divisioona against Korpiselkä on 10 July, overwhelming its defenders by the next morning. Talvela was not satisfied with the level of aggression displayed by Koskimies, however, and replaced him with Lagus. The 5th Divisiooan pursued the retreating 52nd Regiment eastward with light units and reached Tolvajärvi lake on 12 July. The division then turned to the south and advanced along lesser roads, some of these being in a condition so poor that the men had to carry the bicycles that constituted their primary means of transport. On 14 July the 5th Divisioona cut the railway linking Sortavala and Petrozavodsk, and on the next day reached the shore of Lake Ladoga, thereby severing Soviet land routes around the lake. The Soviets had to transfer two regiments and some independent battalions from the Karelian isthmus to close the 'hole' on the eastern side of Lake Ladoga.

By 4 July Heiskanen’s 11th Divisioona had found that the Soviet forces had abandoned their trenches across the border, and then used its superior mobility to encircle and capture them. By 9 July, when the general offensive began, the 11th Divisioona had pushed on to the east from the positions it had taken, crossing roadless terrain and cutting the road linking Korpiselkä, Värtsilä and Suistamo on the eastern shore of Jänisjärvi lake. From there the division threatened an encirclement of the Soviet forces to the south of Korpiselkä and those holding fortified positions in Värtsilä. To prevent being encircled, the Soviets had to fall back farther to the east. The Soviet 367th Regiment was able to hold its positions to the north of Jänisjärvi lake until the defenders of Värtsilä had retreated there by 12 July. Heiskanen maintained the Finnish pressure on the 367th Regiment round the eastern side of Jänisjärvi lake and reached Jänisjärvi itself before driving forward to Lake Ladoga 16 July, where the 11th Divisioona went on the defensive.

Lagus’s 5th Division continued its offensive along the north-east shore of Lake Ladoga. The 452nd Motorised Regiment was moving to the north from the Karelian isthmus, and its first units were set to hold Salmi, where the Tulemajoki river reaches Lake Ladoga. The Finnish forces arrived there on 18 July, and early on the morning of the following day launched the battle by crossing the river 3.1 miles (5 km) to the north of Salmi and by the afternoon cutting the roads to Salmi. On the next day the Finns were able to push into the village, and only small Soviet units were able to escape the encirclement. Salmi had been taken by the early hours of 21 July.

The strengthened 5th Divisioona continued its advance as rapidly as it could, and crossed the old border on 22 July at Rajakontu. Meanwhile, a battle group under Eversti Eino Iisakki Järvinen had secured the left flank of the main thrust by crossing the old border at Känsäselkä and, on 19 July, capturing the villages of Kolatselkä and Palalahti near the Tulemajärvi lake, where it secured the roads to the north and east before continuing its advance to the south. And on 23 July the 5th Divisioona from the west and Eversti Eino Järvinen’s 'Järvinen' Taisteluryhmä (battle group) from the north began their attack on the village of Vitele, which was captured on the following morning. Lagus unsuccessfully tried to encircle the retreating Soviet forces and had by the evening reached the Tuuloksenjoki, but Soviet tanks and artillery managed to stop the advance of his light forces there.

Paalu’s 1st Divisioona had by now neared the front and been allocated to the VI Armeijakunta on 16 July, but it was not until 20 July that it reached the fast-moving front line and released the 'Järvinen' Taisteluryhmä for its attack toward Vitele. From there the advance continued to the north in the direction of Hyrsylä and to the east in the direction of Vieljärvi, which were both taken a few days later. The Soviet 24th and 28th Regiments, parts of the 9th and 10th Regiments, and the 2nd Artillery Regiment began a counteroffensive on 23 July, and after five days the front line was stabilised some 6.2 miles (10 km) to the east of Vieljärvi.

On 21 July the North Front had reorganised its forces by transferring the 168th Division and one regiment of the 71st Division to the 23rd Army, which was responsible for the defence of the Karelian isthmus, and on the same day the 7th Army was reorganised into two operational groupings, namely General Leytenant Maksim A. Antoniuk’s 'Petrozavodsk' Group with one infantry regiment, two motorised regiments, one armoured regiment and a number of independent units, and General Leytenant Vyacheslav D. Tsvetayev’s 'South' Group with a marine brigade, two motorised regiments and a number of smaller units.

Appreciating the likely change in the operational situation, Mannerheim had on 19 July ordered the halt of the Finnish offensive along the line between Vitele and Vieljärvi as there were still strong Soviet forces on the south-western side of the Jänisjärvi lake, and the speed of the advance had opened a gap on the shore of Lake Ladoga on the 5th Divisioona's right flank, where a defence had to be created. Mannerheim’s concerns were very real, as on 19 July General Major Pavlov, commanding the defence of Lake Ladoga’s shoreline, ordered the 4th Marine Brigade to launch probing attacks behind Finnish defences. During the early hours of 24 July the marines landed on the Lunkulansaari and Mantsisaari islands close to Salmi. The 1st Divisioona, 5th Divisioona and 11th Divisioona were committed at the time, so Talvela had to scrape together whatever he could, including a bridge-building company, to drive the attackers back to the lake. With the help of heavy artillery, which destroyed four of the 15 Soviet vessels, the Finns were able to push the marines into three separate mottis (pockets) and defeated the Soviet attempt to reinforce these during the morning of 25 July. The remaining Soviet mottis were destroyed individually.

On 26 July the Soviets landed on Mantsisaari island, and managed to capture almost the whole of this before Talvela could reinforce the Finnish forces there. The fighting continued late into the night of 27 July before the last Soviet resistance had been crushed.

The task of Hägglund’s VII Armeijakunta was to attack on the VI Armeijakunta' right flank toward Sortavala. The isthmus in the area between Lake Ladoga and the Finnish border is comparatively narrow, and the important rail junction of Matkaselkä was only 6.2 miles (10 km) from the border. It was inevitable, therefore, that after the Moscow treaty which had ended the 'Talvisota' the Soviets had started to fortify the border region in some depth. These defences were weakest on the front’s northern sector, so Hägglund decided deliver his corps' main thrust in that region. Reinforced with pioneer units, the 7th Divisioona and all of the corps' artillery were concentrated there, leaving the 19th Divisioona to the south to manage with just its own divisional artillery. The Finnish assault began on the evening of 10 July. As a heavy thunderstorm was sweeping the area, it was decided that infantry would attack without artillery support so that surprise could be achieved. The plan succeeded and most Soviet forces were encircled in their pillboxes, which were then eliminated with artillery support. During the next day, the 7th Divisioona advanced, encircling several Soviet strongpoints. By the morning of 12 July the Finns had broken through the region where the Soviets had prepared minefields and fortifications.

However, Colonel Andrei L. Bondarev’s 168th Division proved to be very tenacious. The division laid a succession of new minefields as it fell back, and at the same time dug new strongpoints and trenches, and skilfully evaded Finnish units trying to flank and encircle it: the 168th Division’s defence was later used as a textbook example for defensive warfare in Soviet military schools. The 7th Divisioona reached the western shore of the Jänisjärvi lake on 13 July and turned to the south. By 15 July the division had reach the rail line linking Sortavala and Petrozavodsk at Pirttipohja, and encircled the defenders there. Hannuksela’s 19th Divisioona had the demanding task of assaulting the best defended section of the 168th Division’s position. Hannuksela decided to break through on a very narrow but deep section at the village of Niinisyrjä: this breach was to be only between 220 and 330 yards (200 and 300 m) wide and 2.5 miles (4 km) deep to create a gap in the fortified border region. Everstiluutnantti Juva’s 58th Rykmentti (regiment) was the spearhead of the assault, which began late in the evening of 10 July. The regiment fought all night and through the next day, advancing 0.9 miles (1.5 km), but it was clear that the regiment lacked adequate artillery for the task, and therefore received additional artillery from the II Armeijakunta. The 58th Rykmentti continued its attack and reached the rear of the Soviet border defences on 12 July. The 168th Division counterattacked to close the breach and encircle the 58th Rykmentti, but the Finns managed to hold their corridor, although the Soviets managed to seal it against effective use with artillery fire. Eversti M. Laurila’s 16th Rykmentti, following the 58th Rykmentti, managed to reopen the corridor by the morning of 15 July.

The 7th Divisioona continued its attack 15 July to the east along the rail line, and two days later breached the Soviet defences on the isthmus between the Jänisjärvi and Vahvajärvi lakes. Meanwhile the 7th Divisioona's 30th Rykmentti and 51st Rykmentti advanced eastward to the Jänisjoki river, where they linked with the 11th Divisioona on the same day. The 30th Rykmentti and 51st Rykmentti cleared the western shore of the Jänisjärvi lake and reached Lake Ladoga by 20 July, then started to clear islands in front of Sortavala. The 7th Divisioona's 37th Rykmentti was under orders to advance to the west along the southern shore of the Vahvajärvi lake to link with the 19th Divisioona and thereby encircle the Soviets between the two divisions. Bondarev appreciated the danger to his division, however, and ordered the 402nd Regiment to fall back. The 19th Divisioona had continued its attack to the south-east, and on 15/18 July there were 25 fierce encirclement and counter-encirclement actions before the Finns managed to capture the main road and cut the rail line linking Sortavala and Matkaselkä, which was taken on 18 July. The Soviets managed to hold the 37th Rykmentti at the village of Särkisyrjä on 18/19 July, and again at the next village, Ilola, on 20/22 July, so securing the line of retreat for the 402nd Regiment. By 25 July the 168th Division had managed to straighten its front line to a more defensible line extending from the Kiteen river through the hills of Tirimäki, Okanmäki and Voinmäki to the Tohmajoki river.

As the Soviets were driven back from the Jänisjärvi valley, the remainder of the 7th Divisioona turned to the south-west and on 25 July crossed the Tohmajoki river. The advance was slow as the Soviets managed to hold their prepared strongpoints on hills, forcing the Finns to encircle them. On 28 July the 7th Divisioona found a gap in Soviet defences and its 30th Rykmentti quickly poured through this to take Voinmäki. The advancing Finns managed to ambush a car carrying the 198th Division’s chief-of-staff, and from him seized documents including the order for a Soviet counterattack on the following day, so all the Finnish units were ordered to halt where they were and prepare to fight a defensive battle.

The Soviet 23rd Army had transferred the 198th Division from the Karelian isthmus to Sortavala with orders to join the 168th Division in this counterattack, whose object was the recapture of the isthmus between the Jänisjärvi lake and Lake Ladoga as this would render parlous the situation of the Finnish forces along the northern side of Lake Ladoga. When the offensive began, on 29 July, it failed to gain ground anywhere as the Soviet forces lacked adequate strength and the captured information had given the Finns time to prepare to meet the attack.

The Finns continued their offensive against the remaining Tirimäki and Okanmäki strongpoints, whose Soviet retention prevent any advance toward Sortavala, on August 3 and captured them two days later.

Meanwhile Laatikainen’s II Armeijakunta had started its own offensive on 31 July at the narrowest point between Lake Ladoga and the Finnish border, quickly penetrated the Soviet defences and advanced toward the north-western shore of Lake Ladoga, threatening Soviet forces with encirclement. The 23rd Army cancelled its planned offensive and ordered the 198th Division to proceed south for a counterattack against the II Armeijakunta. The 168th Division was ordered to withdraw toward Lake Ladoga from 5 August, and the 367th Regiment was given the responsibility of holding Sortavala. Although Sortavala was insignificant in purely military terms and had been neutralised when the Finns captured the islands controlling access to Lake Ladoga on 27 July, it was politically important. Instead of pursuing the 168th Division, therefore, the Finns concentrated on the seizure of Sortavala. On 12 August 7th Divisioona reach the town, which had been taken by 15 August, only small groups of Soviet troops managing to escape the Finnish net.

The II Armeijakunta had severed the rail line linking Viipuri and Sortavala on 6 August.

On 8 August Mannerheim formed the new I Armeijakunta, under the command of Eversti Einar Mäkinen, with Hannuksela’s 19th Divisioona, the 7th Divisioona now commanded by Eversti William Häkli, and Eversti Aarne Blick’s 2nd Divisioona, to clear the western shore of Lake Ladoga. The II Armeijakunta reached Lake Ladoga 8 August at Lahdenpohja, thus capturing the harbour which the 168th Division had been instructed to use for evacuation on 23 July. The Soviet division, together with a number of independent regiments and battalions, continued its retreat toward Lake Ladoga with the 2nd Divisioona pressing from the south-west and 19th Divisioona from the north, while the 7th Divisioona continued its offensive against Sortavala. By 17 August the Soviets controlled a beach-head only only 7.5 miles (12 km) wide and 6.2 miles (10 km) deep, but in the course of the next few days the Soviets concentrated their naval and air units to protect the evacuation of the 168th Division and other units. This evacuation was successful, and the Finns thus captured only small quantities of abandoned matériel including 40 pieces of artillery, eight tanks, 310 cars, 35 tractors and 1,500 horses.

At the northern end of the Finnish main offensive, Oinonen’s 'O' Ryhmä, with the Ratsuväkiprikaati and the 2nd Jääkäriprikaati, was ordered to advance to the old border. Opposing it were parts of the 71st Division’s 52nd and 126th Regiments and the 80th Border Guard Detachment. Many Karelian, Ingrian and Finnish-born communist men served in the Soviet ranks, together with large numbers of Finnish-born veterans of the People’s Army in the 'Talvisota'. The Finns started with probing attacks on 7 July, then launched the main attack and in the south the 2nd Jääkäriprikaati had reached the Tolvajärvi lake by 14 July. From there the brigade wheeled to the north and started encirclement toward the Ägläjärvi lake. The Ratsuväkiprikaati was not as successful, and the Finns were forced to encircle the well prepared Soviet defended hill tops as they were unable to take directly for lack of artillery and air support.

By this time Engelbrecht’s German 163rd Division (less one brigade and a part of the divisional artillery that had been diverted to Salla during transport) had reached the front at the Tolvajärvi lake and attempted to break though the Soviet positions on 21 July with only one brigade, but failed as the Soviet forces were stronger than anticipated. A fresh offensive began on 25 July when two battalions of the German 310th Infanterieregiment and one battalion of the Finnish 56th Rykmentti attacked along the rail line near Näätäoja station. At the Tolvajärvi lake, Engelbrecht decided to use the route the 2nd Jääkäriprikaati had opened and ordered this brigade and one battalion of the German 307th Regiment to capture the village of Ägläjärvi and sever the Soviet supply route to Lake Tolva. The attack failed and the Soviets managed to keep open the road through Ägläjärvi, though they did lose a supply depot during the fighting. Engelbrecht exchanged the Ratsuväkiprikaati for two infantry battalions, which were ordered to maintain a defensive position, and ordered the Ratsuväkiprikaati to cut the road linking the Tolvajärvi and Ägläjärvi lakes by means of an advance through the area’s forests. The attack started on 2 August and two days later the Ratsuväkiprikaati had reached the road and started to move on the Tolvajärvi and Ägläjärvi lakes. On 3 August the 2nd Jääkäriprikaati and German 1/307th Infanterieregiment attacked the village of Ägläjärvi, which they captured on 5 August. On the following day the Finnish and German forces linked with the Ratsuväkiprikaati/e] to the south of the village of Ägläjärvi. The Soviets continued their retreat to the Aittojoki river, where they blew up the bridges and dug in.

The Soviet northern forces, also fearing encirclement from the Ägläjärvi area, abandoned their positions there on 8 August and fell back to the east of Kuolismaa.

On 20 July Heiskanen’s 11th Divisioona had been relieved from Jänisjärvi lake and was moved first into reserve and then to the area between the 1st Divisioona and the German 163rd Division in the area of Hyrsylä on 11 August. The Soviets reinforced their forces in the area with the new 272nd Division on 10 August, and began an immediate attack toward the Vieljärvi lake area against the 1st Divisioona. In five days the Soviets managed to advance just 1.25 miles (2 km), and then only in a few places, before being halted. On 19 August the 11th Divisioona itself went over to the offensive from Hyrsylä to the north, and reached the Petrozavodsk railway and the main road on the following day. From there the Finnish division continued to the north-east toward Suvilahti, which it took on 21 August, and to the north toward Tsalkki, the location of the last usable supply road available to the Soviets.

On 19 August the 2nd Jääkäriprikaati, the Ratsuväkiprikaati and the German 307th Infasnterieregiment stormed over the Aittojoki river. The Ratsuväkiprikaati tried to encircle the defending Soviet forces, but the latter recognised their precarious situation and quickly pulled back, managing to extricate most of their strength to the east before the 11th Divisioona cut their line of retreat at Tsalkki on 23 August. With the capture of Suojärvi, the last town in Ladoga Karelia had been liberated.

Farther to the south, the Finns undertook a parallel offensive to liberate the Karelian isthmus under the supervision of Oesch’s Kannaksen V
Voimien Komentajan Päämaja
(Headquarters of the Commander of the Isthmus Forces). Here, between the south-western shore of Lake Ladoga and the northern shore of the Gulf of Finland, the new headquarters, which had come into existence on 14 June, deployed three major formations in the form of Talvela’s II Armeijakunta, Laatikainen’s V Armeijakunta and Oesch’s IV Armeijakunta. The first comprised Blick’s 2nd Divisioona, Eversti Niilo Hersalo’s 15th Divisioona and Eversti Aaro Pajari’s 18th Divisioona to the north of the Vuoksijoki river; the second comprised only Eversti Jussi Sihvo’s 10th Divisioona; and the last comprised Eversti Kaarlo Viljanen’s 4th Divisioona, Eversti Einar Vihma’s 12th Divisioona and Eversti Claes Winell’s 8th Divisioona defending the coast.

The V Armeijakunta was disbanded on 29 June, its headquarters being revised to become the headquarters of the new VI Armeijakunta, and the 10th Divisioona was then attached first to the IV Armeijakunta and from a time late in July to the II Armeijakunta as a reserve.

Facing these were the Soviet XIX Corps (142nd and 115th Divisions) and L Corps (43rd and 123rd Divisions), with the X Mechanised Corps (21st and 24th Tank Divisions and 198th Mechanised Division) in reserve and the divisional-strength 22nd Karelian Fortified Region holding the coast. At the end of June the X Mechanised Corps was transferred to the area south-west of Leningrad to bolster the Soviet defence against the advance of Generalfeldmarschall Wilhelm Ritter von Leeb’s Heeresgruppe 'Nord' from the south-west, but left its 198th Mechanised Division as the only Soviet reserve.

As the 'Jatkosota' started, each side had remained at first on the defensive, delivering only small company- or battalion-size probing attacks to improve their tactical positions. Their loss of reserves against the more pressing German assault to the south prompted the Soviets to retreat to a more defensible line at the northern end of the front and they also continued to fortify in depth, creating concrete and wooden strongpoints, digging trenches and laying minefields. The Finns advanced to keep contact, and this situation continued until 31 July and the start of the Finnish offensive. The Soviet fortification programme had been concentrated near the Vuoksijoki river and along the roads, so the Finns concentrated their forces for breakthroughs that were narrow but deep over roadless terrain with the support of pioneers building temporary supply roads through the forests and over the swamps.

Pajari’s 18th Divisioona attacked through the forest against the most northern sector of the 115th Division: rather than following roads, the Finnish division secured an initial crossroads and then advanced through the forest to the next road, where it repeated the process. The crossroads were occupied by stronger units, which had to defend against several Soviet counterattacks with armoured support. On 4 August the Finns managed to encircle and capture the Ilmee crossroads, thus forcing the Soviets to abandon their prepared positions between Ilmee and the border. The main thrust of Hersalo’s 15th Divisioona fell on the 588th Regiment of the 142nd Division, and was again delivered on a width of only 1.25 miles (2 km) with the aid of concentrated artillery fire. After breaching the border fortifications, the division advanced 3.1 miles (5 km) through the forest before coming to the road, thereby bypassing the Soviet defences, which were encircled and captured individually by following units. After six days the 15th Divisioona was only 1.85 miles (3 km) from the rail line linking Viipuri and Sortavala and 9.3 miles (15 km) from the western corner of Lake Ladoga, and thus close to encircling Soviet forces on its left side.

Blick’s 2nd Divisioona decided to trap two battalions of the 461st Regiment holding the village of Tyrjä by encircling the village from the east and pushing the defenders to the Tyrjänjärvi lake with the 7th Rykmentti while the 28th Rykmentti bypassed the village and advanced to the south. With the aid of artillery support the Soviets managed to hold for four days before the encirclement was complete. Some of the men were then able to escape through the forests, but most of them and all their heavy equipment were trapped to the village. The Finns also suffered heavy casualties in the fighting before the capture of Tyrjä opened the road toward the railway crossing at Elisenvaara, and on 5 August 5 the first Finnish units reached the rail line linking Viipuri and Sortavala.

On 4 August General Leytenant Mikhail N. Gerasimov, commanding the 23rd Army, ordered the 198th Division to call off its counterattack near Sortavala and move to the south and join the 142nd Division in an attack on the advancing 2nd Divisioona, the 43rd and 115th Divisions being instructed to check the Finnish reserves. The counterattack failed and the 115th Division retreated to the Helisevänjoki river at a location where hills and the river formed good defensive positions against the 18th Divisioona. This formation advanced to the Helisevänjoki river and reached the rail line linking Viipuri and Sortavala at the Inkilä crossroads on 8 August.

Sihvo’s 10th Divisioona was ordered to advance in the area between the 15th Divisioona and 18th Divisioona, and on 6 August reached the rail line connecting Viipuri and Sortavala. The 10th Divisioona continued to attack in the direction of the rail line linking Käkisalmi and Hiitola, but the Soviet forces managed to keep the rail and road lines open until 8 August, when the 10th Divisioona captured the village of Hiitola. When the 10th Divisioona's first troops reached Lake Ladoga on the next day, the last land connection to the Soviet troops on the north-western shore of Lake Ladoga was severed. The Soviets tried to reopen the connection with powerful counterattacks on 10/11 August, but were unsuccessful.

Meanwhile the 2nd Divisioona's 28th Rykmentti had captured the Elisenvaara rail junction on 9 August, thereby opening rail supply routes to the front from Finland. After the battle of Tyrjä, the 2nd Divisioona's 7th Rykmentti rested for two days as the divisional reserve before continuing the attack along the railway toward Lahdenpohja, which it captured on 8 August, thus dividing the Soviet forces what was now a beach-head. On the same day the 2nd Divisioona was transferred to Eversti Einar Mäkinen’s new I Armeijakunta with an order to clear the northern part of the Soviet beach-head, while the 10th Divisioona and 15th Divisioona cleared the beach-head’s southern part, where the Soviets ordered the 142nd and 198th Divisions to withdraw to Kilpolansaari island for naval evacuation. This withdrawal was executed in an orderly fashion and the Finns were unable to encircle any significant Soviet forces. On 11 August the 15th Divisioona captured the Hiitola railway junction, and on 13 August all the surviving Soviet forces had retreated to the Huiskonniemi peninsula and Kilpolansaari island. Under total air superiority, the Soviets managed to withdraw almost all their men, weapons and equipment from the beach-head and by 23 August the 15th Divisioona, which had been left to maintain the pressure on the Soviets, had cleared the remaining rearguards from the island.

The Soviets planned to start a major counter-offensive on 10 August, and in expectation of this the 23rd Army had received the 265th Division as a reinforcements in the area of Räisälä. The offensive was not directed against the 10th Divisioona and 18th Divisioona, though, but rather toward the opening of passages to the the forces encircled on the north-western shore of Lake Ladoga. Coincidentally, the 18th Divisioona had been resting, and was now ordered to continue its advance on the same day, so when the Soviet attack started at Inkilä, the Finns began their own effort only 3.1 miles (5 km) to the west. The Soviet offensive failed to gain ground, while the Finnish attack cut the Soviets' main supply route and a later Finnish counterattack forced the Soviet forces to retreat south. Finnish troops reached the Vuoksijoki river on 14 August at Antrea (now Kamennogorsk), where they continued clearing the river’s left bank.

The Soviets started to move forces from the south-western side of Viipuri to defend Enso (now Svetogorsk) and to make a counterattack toward Antrea on 16 August, but when the attack failed the Soviets were forced to evacuate the northern bank on 21 August. On the eastern side the Finns advanced to the south-east and reached Vuosalmi and the northern outlet of the Vuoksijoki river on 17 and 18 August respectively. The Finns immediately made an unopposed crossing of the Vuoksi river a short distance to the west of Vuosalmi on 17 August, and by 20 August had secured the beach-head.

The Soviet counterattack on the 10th Divisioona began on 14 August and managed to push the Finns 1.25 miles (2 km) to the north before Finnish reinforcements arrived and checked the Soviet advance. The 10th Divisioona left the shore of Lake Ladoga to the 36th Rykmentti of the 15th Divisioona and concentrated all of its strength against the 265th Division at Räisälä (now Melnikovo). On 15 August the 10th Divisioona began its own attack, which encircled the Soviet defenders of Räisälä on 17 August and captured the town on the next day. From there the division continued clearing the left bank of the Vuoksijoki river’s northern outlet. On 19 August the 43rd Rykmentti of the 10th Divisioona continued to attack southward, and reached Suvantojärvi on 21 August. From there it continued to the eastward with the same division’s 1st Rykmentti.

With all their forces to the north of the Vuoksi river now threatened with encirclement, the Soviets started to retreat from Käkisalmi, which the Finns captured on 21 August. The Finnish attack to the south continued and, as the small border guard units were capable only of delaying this progress, the Finns reached the Taipaleenjoki river and the shore of Lake Ladoga on 23 August. Here the Finnish troops were unable to make an immediate crossing of the river.

The Stavka fully appreciated the serious nature of the Soviet predicament, and on 20 August ordered a retreat to the new but generally unprepared defence line extending from the south-western side of Viipuri northward to the Vuoksi river and then along this waterway to Lake Suvanto and along the Taipaleenjoki river to Lake Ladoga. This decision shortened the front line to a marked degree, but also meant the abandonment of defensive installations the Soviets had prepared along the border during the preceding months. The Finns were preparing to start their own attack along the southernmost part of the border, so when the Soviet retirement was spotted on 21 August, the Finnish forces were ordered into an immediate pursuit.

Although General Major Vladimir V. Kirpichnikov’s 43rd Division managed to man new positions to the north and west of Viipuri, it was unable to prevent Vihma’s 12th Divisioona from advancing along the right bank of the Vuoksijoki and establishing contact with the 18th Division, which was enlarging its bridgehead at Vuosalmi, and during the evening of 22 August the whole right bank was in Finnish hands. General Major Fillip F. Aliabushev’s 123rd Division was currently holding the south-western side of Viipuri, but much of this division’s strength, together with that of General Major Vasili F. Konkov’s 115th Division which had retreated from the upper part of the Vuoksijoki river, was still disorganised as a result of its rapid retreat from their positions. Viljanen’s 4th Divisioona advanced along the Saimaa Canal, pressing the 43rd Division from the north. By 23 August the most southern Finnish formation, Winell’s 8th Divisioona, had cleared the western shore of the Bay of Viipuri as far to the east as the Ykspäänjoki river and begun to prepare a crossing of the bay. During August 23, the Finns had managed to advance from the east to a point 5 miles (8 km) from Viipuri, but during the morning of the following day the 115th and 123rd Divisions started a counterattack on the Finnish forces to the east of Viipuri, probably trying to regain the initiative and force Finns back to the northern bank of the Vuoksijoki river. Aided by heavy artillery fire, the Soviets managed to push the Finns more than 3.1 miles (5 km) in some places, but could not break though the Finnish front, and with the arrival of the Finnish reserve, in the form of the 12th Division's 26th Regiment, which was already moving up as part of a planned troop rotation, the Soviets were in turn driven back to their starting positions on the following day.

The Soviet counterattack did not affect the 12th Division's drive, which had already been ordered and now severed the main rail link between Viipuri and Leningrad on 25 August.

During the morning of 24 August, the 8th Divisioona started to cross the Bay of Viipuri to the Lihiniemi peninsula using the 3/45th Rykmentti, and secured the peninsula in the course of the same day. The Finns continued the attack on the next day, cutting last rail link from Viipuri during the afternoon, and enlarging their beach-head a short distance in width and depth during next two days.

The 12th Divisioona had continued its offensive to the south-west, and cut the main road linking Viipuri and Leningrad on 27 August. On the next day the Stavka authorised the 23rd Army to withdraw from Viipuri and establish a new defensive line along the course of the previous 'Mannerheim Line'. The Soviet forces began an immediate retreat and tried with great vigour to open the roads they needed. At Ylä-Somme they managed to open one road in the evening of 28 August, and during the night they were able to move several truck convoys along this, although under Finnish fire. The artillery fire caused Soviet losses of men and trucks, and the road gradually became so congested that only men on foot were able to pass. During the next two days, the Soviets tried repeatedly to open the rail line along the Bay of Viipuri, but late in the evening of 30 August the 3rd Rykmentti of the 12th Divisioona linked with the 8th Divisioona, and the motti at Porlampai was overrun.

As their attempts to break out of the Finnish encirclement during the next day failed and as this encirclement tightened round them, the Soviets made a final attempt to save the men by abandoning all vehicles and trying to escape on foot through the forests. The ring was already too tight, however, and only small groups managed to escape during this last night. In the morning of the next day the remaining and now completely demoralised Soviet troops started to surrender: 9,000 men surrendered and bodies of another 7,000 were buried, but almost 12,000 men had managed to escape before the ring closed. In this victory the Finns also took 306 pieces of artillery, 55 tanks, 673 trucks, almost 300 tractors and about 4,500 horses.

Along the main road and rail lines between Viipuri and Leningrad, the Soviet order to retreat and form a new defensive line along the old 'Mannerheim Line' came too late, for on the same day the 12th Divisioona captured Leipäsuo and continued its advance to the south-west in the direction of the Kuolemanjärvi river, and to the south-east along the rail line. The Soviet defences at the main road junction of Summa held, but the Finns encircled these defences by breaching the defences at Munasuo. Here the remnants of the 123rd Division managed to check the Finnish advance in only few places, and continued their retreat toward Leningrad.

During the morning of 30 August the 12th Divisioona cut the rail line linking Koivisto and Leningrad on the Kuolemanjärvi river, and reached the coast of the Gulf of Finland during the same day. At Vammelsuu the 12th Divisioona cut the rail line during the evening of the same day, but failed to cut the main road. The division reached the Gulf of Finland here on the following morning. The attack continued east to the Terijoki river, which it reached on 31 August, and arrived at the old border at the Raja river on the next day.

The encircled Soviet forces at Koivisto retreated to the islands, from which they were evacuated to Leningrad by ships of the Soviet navy. The last Soviet defenders of Koivisto were evacuated on 1 November.

On the 12th Divisioon's left flank, from 23 August the 18th Divisioona attacked toa the south-east between the Muolaanjärvi river and the Vuoksijoki river and, by 26 August the division had broken through first lake isthmuses.

Meanwhile the first units of the 2nd Divisioona were starting to relieve the 18th Divisioona in the isthmus between the Kirkkojärvi and Punnusjärvi lakes, and the 10th Divisioona those between the Punnusjärvi lake and the Vuoksijoki river.

After the mottis on the north-western shore of Lake Ladoga had been cleared, the I Armeijakunta was moved to the Vuoksi river, and here took the 10th Divisioona and 15th Divisioona under command. The 18th Divisioona breached the second of the lake isthmuses on 27 August, and after a one-day pause continued its attack towards the Kivennapa (now Pervomaiskoye) crossroads, which it took on 29 August. The attack continued and reached the old border on 31 August. The 2nd Divisioona also reached the old border on the same day. The 10th Divisioona had a harder time of it as the 198th Division had started to counterattack on 29 August.

The Finnish offensive started to gather greater momentum during 30 August, the day on which the 15th Divisioona joined the attack from the other side of the Vuoksi river. The Valkjärvi lake railhead was captured on 31 August and, threatened with yet another encirclement, the Soviet forces were ordered to withdraw from the southern side of the Vuoksijoki river to positions behind the old border. The 15th Divisioona followed the retreating Soviets closely, and by 2 September the Finns had reached the old border along its full length in the Karelian isthmus.

On 20 August, meanwhile, General Waldemar Erfurth, the senior German liaison officer at the Finnish headquarters, notified Mannerheim that Generalfeldmarschall Wilhelm Keitel, head of the Oberkommando der Wehrmacht, was about to request Finnish aid in the assault on Leningrad. Mannerheim explained the practical difficulties of the proposal and also revealed the opposition of both the Finnish political and military leadership to such aid. The government had decided at a time before the start of the campaign that Finland would not attack Leningrad, and only after the military leadership had exerted considerable pressure had the government accepted a modest advance across the old border to take superior defensive positions. When Keitel’s letter arrived, both President Ryti and Mannerheim prepared a negative answer. On 31 August Erfurth again contacted Mannerheim with the proposal that the Finns should cancel their attack into East Karelia and instead attack Leningrad. Ryti and Mannerheim again refused.

On 31 August Mannerheim ordered that the Finnish offensive be halted along the line linking the mouth of the Rajajoki river and Ohta, while the exact halt line on the stretch between Ohta and Lake Ladoga would be determined later, after the Finns had reached the old border there. The object was to shorten the front line without the need to attack the the 22nd Karelian Fortified Region, which was the Soviet defensive area to the north of Leningrad.

In this last phase of the fighting on the Karelian isthmus, the Soviets had six infantry divisions and a number of independent battalions and regiments defending Leningrad from the north, but this nominally potent force was not as effective as it appeared since all of its formations and units were at half strength as a result of the previous hard fighting with the Finns.

The 12th Divisioona had reached its objective by 1 September, but elsewhere the attack started on 2 September. The 18th Divisioona took Mainila on this day and Valkeasaari (now Beloostrov) on the following day. By 7 September both the 18th Division and 2nd Divisioona had reached their objectives between the Rajajoki river and Ohta. Mäkinen, the commander of the I Armeijakunta, ordered his forces to advance to the line linking Ohta, Lempaalanjärvi lake and the old border at Lake Ladoga with the proviso that in the event of determined resistance was met the offensive was to be called to a halt.

On 4 September the attack began, and two days later the 10th Divisioona encircled and destroyed the 941st Regiment at Kirjasalo. The Finnish forces had reached all of their final objectives by 9 September, halted and assumed a defensive posture.

The Soviets quickly learned of the lessened Finnish pressure, and capitalised on this fact: on 5 September two divisions were transferred from the Karelian isthmus into the area lying to the south of the Leningrad to fight the German onslaught. Although the Finnish troops on the Karelian isthmus played no active part in the great siege of Leningrad, their mere presence contributed to the German effort by hampering the delivery of supplies of the city round and across Lake Ladoga.

Farther to the north, the Finnish offensive in East Karelia by the forces of the Karjalan Armeija followed the effective end of Finnish operations in Karelia Ladoga and the Karelian isthmus, and this period of more than one month was used for the strengthening of the forces in this area and the completion of their offensive plans in light of the fact that the Soviets had developed new fortified areas and strengthened their own forces.

When the encirclement battles on the western shore of Lake Ladoga were resolved, Svensson’s 7th Divisioona was redeployed to the junction of the VI Armeijakunta and VII Armeijakunta, a position from which it could assist either of them. The Finnish offensive was launched during the early hours of 4 September at Tuulos, where the largest Finnish artillery barrage to date was unleashed. Immediately after the end of this barrage, the 5th Divisioona crossed the Tuulosjoki river some 4.3 miles (7 km) from its mouth on Lake Ladoga at 05.00. While the river crossing was in itself easily accomplished, the Soviet defence soon strengthened. The Finnish armoured battalion followed the spearhead and helped to destroy strongpoints, and finally the shore road was severed at 11.00. A Soviet counterattack, launched two hours later, managed to encircle the Finns who had reached the shore road, however. When the situation seemed increasingly dangerous to his forces at 14.00, Karhu committed his reserve, the 4th Valon Irrotus (light detachment), and with tank support this managed to break the encirclement at 17.30, and in the battle that followed scattered the Soviet forces and reached the coast of Lake Ladoga, thus cutting the retreat route of the forces still between them and the Tuulosjoki river. During the night the encircled Soviet forces were destroyed. The battle effectively shattered the Soviet 3rd Marine Brigade and the 419th and 452nd Regiments, and thereby opened the route to Olonets.

With the breakthrough area secured, the Detachment 'Lagus' passed through the 5th Divisioona toward Olonets, which it captured on 5 September after only a short fight. From there the detachment advanced through the night toward the Svir river, which its leading units reached at 05.00 on 7 September. Here the Irrottautuminen 'Marttinen' (Martinnen detachment ) was hived off the Irrottautuminen 'Lagus' with an armoured battalion, and pressed on to the east from Olonets to take the northern end of the rail bridge over the Svir river and sever the western branch of the Soviets' vital Murmansk railway on the morning of 8 September.

On the 5th Divisioona's left flank, the 17th Divisioona was not as successful, the Soviet 3rd Division being able to hold its positions at Säntämä.

Farther to the north the 17th Divisioona fared better, and its 13th Rykmentti reached the road linking Olonets and Petrozavodsk on the evening of 5 September. Here the 34th Rykmentti continued its advance to the south along this road. From Olonets the 44th Rykmentti, which was part of the Irrottautuminen 'Lagus', started to move northward on 6 September along the road toward Nurmoila, which it took on the following morning. This meant that all of the 3rd Division’s road communications had been cut, and this Soviet division quickly broke away from Säntämä and tried without success to recapture Nurmoila.

During 7 September the Finnish forces captured the whole length of the road between Nurmoila and the position held by the 34th Rykmentti, but by abandoning their vehicles most of the 3rd Division’s men managed to break through the Finnish lines on 8 September and cross the road to the east, thus escaping to the roadless forests there.

On reaching the Svir river, the 17th Divisioon started to clear both banks toward the east from the bridge where tahe Murmansk railway crossed the Svir river. The Soviets had reinforced the area with the new 314th Division and the Finnish advance was slow, but by 22 September the Finns had consolidated a bridgehead some 3.1 to 6.2 miles (5 to 10 km) deep and 25 miles (40 km) on the south bank of the Svir river.

On the 7th Divisioona's northern flank , the 1st Divisioona and 11th Divisioona were preparing to attack along the road connecting Olonets and Petrozavodsk road, and took bridgeheads across the Säpsänjoki river on 31 August. As elsewhere, the Soviets had prepared defences along the roads, so the Finns advanced through the trackless forests to encircle the defending Soviet forces. On 7 September the Finnish advance cut the road linking Aunus and Petrozavodsk at a point to the north of the Prääsä crossroads, which was itself captured on the following day. This isolated the 9th and 24th Regiments of the 272nd Division from their supply lines. The 1st Divisioona attacked these forces and on 7 September reached the main road.

On 11 September the Soviets started a counterattack from both sides against the Finnish roadblock at Prääsä in an attempt to reopen the road to Petrozavodsk. The effort had failed by 13 September, and this meant that the Soviet forces had no other option than to abandon their heavy equipment and retreat to the east through the forests, which they did during the next three days. After the area had been cleared of Soviet forces, the 11th Divisioona continued the attack on 20 September with an advance along the main road, cutting it every 1.25 mules (2 km) and thereby forcing the defenders to abandon their positions. By 24 September the 11th Divisioona had reached the village of Puoliväli, just 12.5 miles (20 km) from Petrozavodsk on the western shore of Lake Ladoga.

Lagus had meanwhile gathered his forces at the rail bridge over the Svir river, and on 18 September resumed the offensive with an eastward attack along the river to the village of Ostretsina, where he turned to the north in the direction of the village of Latva.

Between 15 and 20 September the 7th Divisioona had built more than 18.5 miles (30 km) of road through the swamps and marshy forests towards the station at Latva on the rail line to Murmansk. The object of these operations was the double encirclement of the 3rd Division and a number of independent battalions which had prepared defences along the rail line and were supported by an armoured train, impenetrable by Finnish anti-tank weapons. The Finnish attack achieved surprise, cut the rail line severed and took Latva on 21 September. The encircled Soviet forces started an immediate retreat along the rail line to the north, and with the help of the armoured train managed to break out of the encirclement and pull back to the north on 22 September. Not bothering to wait for the end of the fighting at Latva station, Lagus ordered two battalions under the command of Everstiluutnantti Björkman to attack to the north from Latva village. On 24 September these two battalions reached the shore of Lake Onega at the village of Derevjannoje, thus severing the Soviet northern forces' last land connection with the area to the south of Petrozavodsk. On 25 September Lagus ordered Björkman to cut the rail line again near Petrozavodsk, a task he achieved two days later at Orsega. One day later still, Björkman’s force was only 2.5 miles (4 km) from Petrozavodsk but had to halt as the two battalions were needed in Orsega, where Soviets were trying to break out of encirclement.

On 29 September the Soviets managed to force their way out through the Finnish line at Orsega and advance 3l.1 miles (5 km) to the north before being halted. The 7th Divisioona was following the Soviet forces and on 30 September there was fierce fighting at Orsega. The 9th Rykmentti of the 7th Divisioona attacked to the south along the road which followed the western shore of Lake Onega, and reached the Svir river on 2 October. An immediate crossing was planned but had to be postponed as the tired troops refused to cross the river during the night. The crossing was then made at 14.00 on 6 October, and in the course of the next week the 7th Divisioona established a bridgehead 6.2 miles (10 km) deep on the southern bank of Svir river before the arrival of 114th Division halted the Finnish advance. Both sides then dug in and started to create defensive positions.

On 26 September the 1st Divisioona and 11th Divisioona continued their attack toward Petrozavodsk. Appreciating the danger they were in, the Soviet forces started to evacuate Petrozavodsk, so when the 11th Divisioona cut the main road and rail line to the north from Petrozavodsk on 30 September most of the Soviet forces had pulled back. The town’s last defenders were evacuated by water across Lake Onega, and the Finns captured Petrozavodsk during the morning of 1 October. The 3rd Division realised that the road to the north was blocked, and after destroying its heavy equipment, including the armoured train, retreated to the forests and started a long trek to the south. The 30th Rykmentti spearheaded the Finnish pursuit, and after two weeks it was only a few hundred men of the 3rd Division who escaped over the Svir river.

On the 11th Divisioona's left flank the 4th Divisioona advanced along the rail line linking Sortavala and Petrozavodsk. The Soviets had created strong defences in this area before the 'Talvisota', so the Finnish advance was considerably slower than had been anticipated, and the 4th Divisioona was still 7.5 miles (12 km) from Petrozavodsk when the town fell.

Farther to the north was the 'Oinonen' Ryhmä (2nd Jääkäriprikaati and Ratsuväkiprikaati) with orders to advance to the north-east. There were only two roads through the forests which the 'Oinonen' Ryhmä could use, so the 71st Division concentrated its strength to hold one of these and on 16/21 September could therefore drive the 2nd Jääkäriprikaati back almost 6.2 miles (10 km) before being forced to retreat as the attack of the Ratsuväkiprikaati threatened it with encirclement. The 'Oinonen' Ryhmä continued its pressure on the 71st Division, and reached the Vatselänjärvi lake on 29 September, thereby opening the way to the east.

After the capture of Petrozavodsk, the Army of Karelia was ordered to continue the offensive to the north along the rail line and capture the string of lake isthmuses up to the Suununjoki river. The 1st Divisioona crossed the Bay of Petrozavodsk to Cape Gromovskoye on 2 October and had cleared the southern part of the cape by 7 October. The first isthmus was breached by the 4th Divisioona on 5 October, but the Finnish advance was slowed by the 1072nd Regiment’s rearguard actions. The 1st Divisioona therefore took responsibility for the attack, and the 5th Rykmentti was transferred from the 4th Divisioona to the 1st Divisioona. The newly arrived 29th Rykmentti was despatched from Petrozavodsk to bolster the 1st Divisioona still further, and on 18 October the Finns finally reached the Suununjoki river.

The 4th Divisioona continued its attack to the north on the western side of the lakes, leaving only small detachments to secure the next two isthmuses, until it linked with the 'Oinonen' Ryhmä, which had advanced to the east in the direction of the isthmus between the Sunjärvi and Pälläjärvi lakes on 13 October. The Finnish attack continued northward along the western shore of the Pälläjärvi lake, and on 19 October the 4th Divisioona captured the crossroads at the Juustjärvi lake, so opening the way toward Karhumäki before the 126th Regiment passed the crossing, whereupon the Soviet regiment abandoned its heavy equipment and retreated to the north through the forests.

The 8th Divisioona had been moved from the Karelian isthmus to the Porajärvi lake area, which had been captured by the 'Kuusjärvi' Prikaati on 12 October, when the Soviet forces started to retreat from their prepared positions as the 4th Divisioona advanced toward the Juustjärvi lake. On 15 October the 8th Divisioona, strengthened by the arrival of the 'Kuussaari' Prikaati, started the attack across the Suununjoki river and on 18 October captured the crossroads at the Jänkäjärvi lake, from which it continued toward the Juustjärvi lakje, where it met the 4th Divisioona on 20 October, and toward the Seesjärvi lake which it reached on 19 October. The 8th Divisioona continued to clear the southern shore of the Seesjärvi lake, and on 1 November took the village of Maaselkä before being compelled to halt by the arrival of the 289th Division.

After a three-week pause for preparation, the Finns resumed their offensive on 21 November and drove the Soviets back against the lake’s western shore. The Soviets managed to escape over the frozen lake on 28 November. The Finns' attempt to take the station at Maaselkä failed after the 263rd Division reached the station right before them. As it it was now clear that the offensive could not now be continued to the railway station, the 8th Divisioona was ordered to prepare defensive positions.

The capture of the Juustjärvi area threatened the long right flank of Soviet forces defending the eastern bank of the Suununjoki river, so the 4th Divisioona, reinforced with the 45th Rykmentti, was ordered to advance to the shore of Lake Onega and isolate the Soviet forces in that area. The attack started on 20 October and by 24 October had taken the village of Mäntyselkä at the southern end of the Semsjärvi lake, but failed to advance from there. The 26th Rykmentti was ordered to encircle the Soviets by passing round the lake, and in the early morning of 27 October it captured the village of Kumsa, thus severing the Soviet rear and forcing a Soviet retreat. Meanwhile the 45th Rykmentti had advanced through the forest by small paths and improved them sufficiently for motor vehicles to use the route, and reached the railway near Käppäselkä station on 27 October. In the following two days the regiment captured the station and an armoured train which had become stuck there.

At the same time, 27 October, the main Finnish offensive across the Suununjoki river began, the Ratsuväkiprikaati securing the initial bridgehead. On the next day, the 2nd Jääkäriprikaati crossed the river and advanced toward Kontupohja, while the Ratsuväkiprikaati turned to the north to race round the Santalanjärvi lake. On the following day the 1st Divisioona also crossed the river and, with the 2nd Jääkäriprikaati, attacked Kontupohja straight from the march. This first assault failed, and the Finns therefore paused to prepare their next assault.

The 313rd Division defending Kontupohja had noticed that additional Finnish units were now threatening its line of communications to the north and therefore began to withdraw from Kontupohja during the evening of 2 November just before the Finnish assault planned for the following morning. The Finns captured the town, which had been destroyed by fire, before 24.00 and continued in pursuit of the Soviets. Despite the fact that the Cavalry Brigade had cut the railway line and the main road to the north, the Soviet division managed to retreat using the hastily built road between the main road and the lake’s shore.

The Soviet situation was now improving as the front shortened and had its flanks anchored on the the lakes. The arrival of reinforcements had also improved the balance of forces, which now took the form of three Finnish divisions and two brigades against four Soviet divisions and one brigade. The high hills to the south and west of Karhumäki also provided natural defensive positions which were improved by extensive field fortifications, and the Finnish advance stopped on November.

During the next two weeks the Finns planned a renewed offensive, and this began on 21 November as the 1st Divisioona started an attack which drove a wedge 3.1 miles (5 km) deep into the Soviet defences before being stopped. On the northern side of Karhumäki, the 4th Divisioona had to halt only 2.5 miles (4 km) from the centre of the town on 19 November. Another Finnish attempt began on 29 November, and by 2 December this had breached the town’s outer defences on the western side. Meanwhile Lagus’s 1st Jääkäriprikaati had reached the front and was committed on 4 December. During the morning of the following day, the 4th Divisioona and 1st Jääkäriprikaati penetrated the Soviet line from the north and west respectively, and advanced to the town. The 2nd Jääkäriprikaati followed immediately behind the 1st Jääkäriprikaati and started the clearance of the town as the 1st Jääkäriprikaati continued quickly to the east in the direction of Poventsa, which it reached on the next day, thus closing the White Sea Canal. Small units crossed the canal and advanced a short distance before returning to Poventsa, where they went onto the defensive. During the night of 8/9 December Soviet pioneers blew the canal’s locks, and the resulting flood broke the banks protecting Poventsa.

To the north of the Karjalan Armeija, Eversti Erkki Raapana’s 14th Divisioona had been instructed to advance to the Rukajärvi lake in the area held by the 337th Regiment of the 54th Division and the 73rd Border Guard Detachment. Here the Soviet defence was based on an area of field fortifications some 9.3 to 12.5 miles (15 to 20 km) deep. The first Finnish patrols crossed the border on 1 July, and the general advance started two days later. The defence managed to delay the Finnish advance, and it was 8 July before the Finns captured Repola. The advance continued 11 July as the Finns crossed the Lieksajärvi lake and started to encircle Soviet forces defending narrow isthmuses.

The Finns completed their envelopment by 21 July and, as their attempt to reopen the road to the east failed on 23 July, the Soviets started to evacuate personnel over the Roukkulanjärvi lake. The evacuation was only partially successful: more than 100 men were drowned and 300 captured. The Omelia motti surrendered on 24 July.

For lack the light units which might have be able to spearhead a rapid advance, the Finns were able to advance to the east only slowly, and the next battles were fought between 30 July and 12 August for control of the Ontrosenvaara hills, where the 54th Division had been reinforced with elements of the 137th Regiment and 71st Border Guard Detachment. When these forces proved incapable of checking the Finnish attack, the 7th Army ordered a new 27th Division to be formed in the area. The Soviets had prepared positions on Rukavaara hill only a short distance to the east, the retreating forces manned these positions and managed to halt the Finnish advance for three weeks. On 3 September the Finns attacked once more, encircling the hill and forcing the defenders to evacuate their positions on 8 September. The Finns took the village of Rukajärvi on 11 September, and crossed the Onkajoki river on 15 September. After advancing only another 1.25 miles (2 km), the Finns reached new Soviet positions which they could not take straight off the march.

Though the 14th Divisioona had not reached all its planned objectives, the target which Mannerheim had set had been achieved with the capture of the Rukajärvi lake area, so the 14th Divisioona was ordered to halt and go over to the defensive.

In the sparsely populated northern half of the Finnish front, where the Germans had operational command, the objectives were the securing of the Finish port and nickel mines at Petsamo in 'Rentier' (i), the seizure of the port city of Murmansk and the severance of the rail line connecting this city with the rest of the USSR in 'Platinfuchs', and the seizure of Salla and Kestenga followed by an advance to the White Sea at Kandalaksha and Loukhi in 'Polarfuchs' (i) within the overall context of the 'Silberfuchs' plan. Murmansk was the only year-round ice-free port in the north of the USSR, and its availability as a base threatened the strategically important nickel mining industry at Petsamo.

'Silberfuchs' was undertaken by von Falkenhorst’s Armee 'Norwegen' using Dietl’s Gebirgskorps 'Norwegen' with the 2nd Gebirgsdivision and 3rd Gebirgsdivision in the north against Murmansk, Feige’s XXXVI Gebirgskorps with the 169th Division, SS Kampfgruppe 'Nord' and Finnish 6th Division in the centre against Salla and then Kandalaksha, and Siilasvuo’s Finnish III Armeijakunta with the Finnish 3rd Divisioona in the south against Kestenga and Ukhta, and then Luki, Kem and Belomorsk.

Though military operations during 1942 and 1943 were limited, the Finnish front did see some fighting. Early in 1942 the forces of Frolov’s Karelian Front tried to retake Medvezhyegorsk, which had been lost to the Finns late in 1941 and, with the arrival of spring, the Soviets also went on the offensive on the Svir front as well as the Kiestinki region. All these Soviet offensives started promisingly, but were soon checked and then driven back as a result of the fact that the Soviets overextended their resources or ran into very determined Finnish resistance in prepared positions. After Finnish and German counterattacks in the Kiestinki area, the front had in fact moved very little.

In September 1942, the Soviets made another attempt at Kriv near Medvezhyegorsk, but in five days of fighting managed to push the Finns back only 545 yards (500 m) over a frontage of 0.6 mile (1 km).

Unconventional warfare was also fought in both the Finnish and Soviet wilderness areas. Finnish long-range reconnaissance patrols organised by both the Finnish headquarters using the 4th Itsenäinen Pataljoona (independent battalion) and local units patrolled beyond the Soviet lines. In the summer of 1942 the Soviets had formed the 1st Partisan Brigade, which was 'partisan' only in name as it was essentially a force of more than 600 men and women on long-range patrol. The 1st Partisan Brigade was able to infiltrate beyond Finnish patrol lines but was found and largely destroyed early in August 1942 near the Seesjärvi lake. Partisan activity in East Karelia was supposedly focused primarily on Finnish military supply and communication targets, but almost two-thirds of the attacks on the Finnish side of the border targeted civilians, killing 200 persons and injuring 50.

Though Vitse Admiral Vladimir F. Tributs’s Red Banner Baltic Fleet entered the 'Great Patriotic War' and 'Jatkosota' in a strong position, the effective German use of mine warfare and air superiority, in combination with the German land forces' swift advance through the Baltic states toward Leningrad, forced the Soviet navy to evacuate its several Baltic Sea bases to Kronstadt and Leningrad at the head of the Gulf of Finland. The Soviet maritime evacuations from Tallinn and Hanko were very costly, and the withdrawal to the eastern end of the Gulf of Finland, left nearly the whole of the Baltic Sea as well as many of its islands to the Germans and Finns. Although the Soviet navy had departed in a great hurry, the naval mines it had managed to lay before and during the evacuations caused casualties both to the Germans and the Finns, including the loss of Ilmarinen, one of the two Finnish coastal defence ships.

Although Soviet submarines continued to be a limited threat to German traffic in the Baltic, the withdrawal of the Soviet navy in effect made the Baltic a 'German lake' until the second half of 1944. The Baltic Fleet still operated from the besieged city of Leningrad. Early in 1942 Soviet forces recaptured the island of Gogland but lost both Gogland and Bolshoi Tyuters to the Finns later in the spring of 1942. During the winter of 1941/42, the Baltic Fleet made the decision to use the large Soviet submarine fleet for offensive work. Though initial submarine operations in the summer of 1942 were successful, the German and Finnish navies soon stepped up their anti-submarine efforts, making the Soviet submarine operations later in 1942 very costly. The Soviets' submarine offensive persuaded the Germans to lay anti-submarine nets as well as supporting minefields between Porkkala and Naissaar, and this was a combination which proved an insurmountable obstacle for the Soviet submarines.

Finland began actively to consider a way to extricate itself from the war after the huge German defeat in the Battle of Stalingrad, which ended in February 1943, and a new cabinet was formed with peace as its highest priority. Negotiations were conducted intermittently during 1943/44 between Finland on the one side and the Western Allies and the USSR on the other, but no agreement was reached. Iosef Stalin, the Soviet leader, then decided to force Finland to surrender, and there followed a bombing campaign on Helsinki. In February 1944 this air campaign included three major air attacks involving a total of more than 6,000 sorties, but the Finnish anti-aircraft defences managed to repel the raids and only about 5% of the Soviet bombs hit their intended targets. Helsinki’s air defence arrangements included the strategic placing of searchlights and fires as decoys outside the city to lure the Soviet bombers to drop their payloads in what were actually unpopulated areas. Major air attacks also hit Oulu and Kotka, but because of radio intelligence and effective anti-aircraft defences, the number of casualties was small.

The start of the end for Finland was signalled by the launch of the Soviet 'Vyborg-Petrozavodsk Offensive Operation' on 9 June 1944, and on 4 September a ceasefire ended military actions on the Finnish side, the USSR ending hostilities exactly 24 hours later. An armistice was signed in Moscow on 19 September.

Finland had to make numerous concessions. The USSR regained the borders of 1940, with the addition of the Petsamo area, and the Porkkala peninsula near Helsinki was leased to the USSR as a naval base for 50 years. The Finnish army was to be demobilised rapidly, though Finland was first to expel all German troops from its territory within 14 days and, as the Germans did not leave Finland by the given deadline, the Finns had to fight their former co-belligerents in the Lapland War.

Finland was also required to clear the minefields in Karelia (including East Karelia) and in the Gulf of Finland.

As they retreated toward northern Norway in 'Birke', the German forces had also undertaken extensive mining of northern Finland. Mine-clearance proved to be a long undertaking, especially in the sea, and lasted to 1952: 100 Finnish soldiers were killed and more than 200 wounded during this effort, most of them in Lapland.

Large numbers of civilians who had been relocated into Finland from Karelia in 1939/40 had moved back into Karelia during the war, and now had to be evacuated once again: of the 260,000 civilians who had moved back into the Karelia only 19 chose to remain and become Soviet subjects.

The 'Jatkosota' had involved some 530,000 Finnish and 220,000 German troops, and the Soviet strength increased from 450,390 in June 1941 rising to 650,000 in June 1944. So far as casualties are concerned, the Finns lost 63,204 dead or missing, 158,000 wounded, 939 civilians killed in air raids, 190 civilians killed by Soviet partisans, and between 2,377 and 3,500 taken prisoner. The Germans lost 14,000 dead or missing and 37,000 wounded. According to the Finns, the Soviets lost 201,000 dead or missing, 64,000 taken prisoner, 385,000 wounded, 190,000 hospitalised by sickness, and between 4,000 and 7,000 civilians killed.