The 'VKT-linja' was the Finnish third of four defensive lines on the Karelian isthmus against the Soviet forces of General Leonid A. Govorov’s Leningrad Front, and extending between Viipuri on the north coast of the Gulf of Finland via Kupersaari and Vuosalmi on the Vuoksi river and lake system to Taipale on the south-western shore of Lake Ladoga (summer 1944).

By the summer of 1944, the Soviets had decided to knock Finland out of the 'Jatkosota' (Continuation War) so that they could concentrate their entire strength against the Germans. On 21 June, 11 days after the Soviet forces had started their 'Vyborg Offensive Operation' within the context of the 'Vyborg-Petrozavodsk Offensive Operation' in the Karelian isthmus between Lake Ladoga and the Gulf of Finland using General Leytenant Aleksandr I. Cherepanov’s 23^rd Army on the right and General Polkovnik Dmitri N. Gusev’s 21^st Army on the right, the Stavka ordered Marshal Sovetskogo Soyuza Leonid A. Govorov’s Leningrad Front to breach the 'VKT-linja' at Tali (Paltsevo) and then to advance to Lake Saimaa with a view to an advance on Helsinki along the northern side of the Gulf of Finland. By this time the Soviet forces had penetrated the 'Päälinja' main line closest to Leningrad and then the 'VT-linja' second defence line.

For this task Govorov used Gusev’s 21^st Army, whose 15 divisions included the strength of the XXX Guards Corps (45^th, 63^rd and 64^th Guards Divisions), XCVII Corps (178^th, 314^th, 358^th and 372^nd Divisions), CVIII Corps (108^th Division) and CIX Corps (72^nd, 109^th and 286^th Divisions). On the other side of the front, the Finnish forces were grouped under the command of Kenraaliluutnantti Karl Lennart Oesch’s Isthmus Forces with Kenraaliluutnantti Taavetti Laatikainen’s IV Armeijakunta 1 (corps), with air support provided by Everstiluutnantti Gustaf Magnusson’s 3^rd Lentorykmentti (air regiment) (33 Messerschmitt Bf 109 and 18 Brewster Buffalo fighters as well as one Fokker C.X reconnaissance aeroplane), and Eversti Olavi Sarko’s 4^th Lentorykmentti (33 Bristol Blenheim, 12 Junkers Ju 88 and eight Dornier Do 17Z bombers). There was also a German presence in the form of Oberstleutnant Kurt Kuhlmey’s Gefechtsverband 'Kuhlmey', which reached Finland on 16 June and eventually mustered some 23 to 43 Focke-Wulf Fw 190A-6/F-8 fighters and ground attack aircraft, 24 to 30 Junkers Ju 87D dive-bomber/attack aircraft, and one to eight Bf 109G-8 reconnaissance fighters); and Hauptmann Hans-Wilhelm Cardeneo’s 303^rd Sturmgeschützbrigade which arrived in Finland on 22 June with 22 StuG III Ausf G assault guns and nine StuH 42 assault howitzers.

The first major engagement after Viipuri in the Soviet offensive was the Battle of Tienhaara, which was fought in the area to the north of Viipuri on 22 June. After they had lost Viipuri, the Finns concentrated their defence in the Tienhaara region, which offered good defensive terrain with a nearby waterway cutting the already narrow battlefield into several islands.

As noted above, the Soviet offensive had started on 10 June and in matter of days broke through the Finnish defence lines in the southern part of the Karelian isthmus. On June 20 the advancing Soviet forces were already outside Viipuri. Eversti Armas Kemppi’s (from 22 June Eversti Yrjö Sora’s) 20^th Prikaati (brigade) had been transferred to defend the city, but this unit had only inadequate supplies and lacked effective anti-tank weapons as it had neither 75-mm (2.95-in) Pak 40 anti-tank guns and knowledge of and training in the use the few available Panzerfaust and Panzerschreck anti-tank weapons. The 20^th Brigade was therefore not prepared to cope with a Soviet armoured assault, led by the CVIII Corps' 90^th Division supported by 260^th Separate Heavy Breakthrough Tank Regiment and 1238^th Self-Propelled Gun Regiment. The brigade’s resistance crumbled swiftly, and many of its men fled either in panic or under supposed orders to withdraw.

The 61^st Jalkaväkirykmentti (infantry regiment), which was composed entirely of Finnish Swedes and volunteers from Sweden, under the command of Everstiluutnanti Alpo Marttinen of Kenraalimajuri Alonzo Sundman’s 17^th Divisioona (division) reached the isthmus from Svir on 22 June, immediately after the loss of Viipuri, and deployed for the defensive at Tienhaara, which is located along the coastal highway leading to the north from Viipuri toward inner Finland, on the shore of Kivisillansalmi. Possessing strong artillery support and also the co-operation of he Gefechtsverband 'Kuhlmey', the regiment was able to keep the Tienhaara region including the Kivisillansalmi while defending against repeated attacks by the 90^th and 372^nd Divisions supported by strong artillery.

After the battle the Soviet forces attempted to push to the north but failed to break through the Finnish lines. Govorov decided that further attempts to cross the waterway would be too costly and time-consuming, and instead concentrated the bulk of his forces into the Juustila-Ihantala area and thereby contributing to the events which led to fighting in the Tali-Ihantala region. The Finnish forces held to Tienhaara (Seleznyovo in Russian) until the ceasefire in the end of summer 1944.

The Battle of Tali-Ihantala which followed between 25 June and 9 July was fought in a small area between the northern tip of the Bay of Viipuri (known to the Soviets as Vyborg) and the Vuoksi river around the villages of Tali and Ihantala some 5 to 8.75 miles (8 to 14 km) to the north-east of Viipuri. The Soviet forces were grouped to the east of Viipuri and attacked through the southern village of Tali along a north-westerly axis toward Ihantala (Russian Petrovka). This was the only terrain in this sector of the front suitable for armoured forces to break out of the Karelian isthmus, and is an area 6 miles (10 km) wide broken by small lakes and limited by Saimaa Canal in the west and the Vuoksi river in the east.

Between 20 and 24 June the Finns had been limited to the defensive, their 18^th Divisioona (6^th Jalkaväkirykmentti, 48^th Jalkaväkirykmentti and 28^th Itsenäinen Pataljoona (independent battalion), the 3^rd Prikaati (four battalions) and the 3/13^th Jalkaväkirykmentti fighting the XCVII and CIX Corps and the 152^nd Tank Brigade. The Finns suffered heavily from the severity of the Soviet artillery and air bombardments, but nonetheless put up a strong defence which stalled the Soviet advance long enough for Finnish reinforcements to join the battle.

The fighting on 25 June started at 06.30 with a heavy artillery bombardment and air attack, followed by a major Soviet offensive from Tali at 07.30. The goal of the attack was to reach the line linking Imatra, Lappeenranta and Suurpäälä before 28 June. The XXX Guards Corps had now also joined the battle. The 21^st Army tried to break through along each shore of Lake Leitimojärvi: that on the eastern side was stopped after 1.85 miles (3 km) by the 4^th Division, and that on the western side comprised the 45^th Guards Division and CIX Corps, which became embedded in the defensive positions around the hills of Konkkalanvuoret defended by Everstiluutnantti Väinö Forsberg’s 48^th Jalkaväkirykmentti. However, Soviet armour of the 27^th Tank Regiment was able to force its way to the Portinhoikka crossroads. The Soviets also attacked with the 178^th Division over the Saarela strait, which was defended by the 1^st Pataljoona (battalion) of Everstiluutnantti Reino Inkinen’s 6^th Jalkaväkirykmentti, but the attack was thrown back. Meanwhile, the XCVII Corps attacked the 3^rd Prikaati's position but gained little ground.

Even so, at this stage of the fighting the situation was very critical for the Finns, whose units were at risk of being cut off and surrounded. This would inevitably have led to the defeat of the IV Armeijakunta and the loss of the 'VKT-linja', but the Finns were able to organise a counterattack with the reserves of the 18^th Divisioona, parts of the 17^th Divisioona and some battle groups of the 4^th Divisioona. Later on the afternoon the Panssaridivisoona entered the fray and succeeded in driving the Soviet attack on the western side of Lake Leitimojärvi back to its start line. Apart from six tanks captured by the Finns, the 27^th Tank Regiment was destroyed.

The next stage of the battle lasted from 27 to 30 June. More Finnish units joined the battle along with the Germans of the 303^rd Sturmgeschützbrigade. The Finnish units had become spread out and mixed in the battle, which made the organisation of a concentrated defence difficult. The Finnish units were therefore reorganised into the Battle Group 'Björkman' and Taisteluryhmä 'Puroma' (battle group).

The Soviets also reinforced their forces with the CVIII Corps. At this stage the Soviet forces included at least one armoured brigade, two armoured breakthrough regiments and four assault gun regiments.

The Finns tried to regain the initiative by attacking the 46^th Guards, 63^rd Guards, 64^th Guards and 268^th Divisions and the 30^th Guards Tank Brigade, which had broken through to the east of Leitimojärvi, from three directions in order to isolate the individual Soviet divisions. The two battle groups managed to advance to within 0.6 mile (1 km) of each other but failed to surround the Soviet divisions, which had established a hedgehog defence around Talinmylly. The Finnish attack failed because of determined and skilled Soviet resistance, especially with massed tanks and artillery. However, the attack did serve to give the Finnish defenders 72 hours of respite at the time when the fresh 6^th Division and 11^th Division reached the battlefield.

Several tank battles took place during this fighting, and on 28 June air activity was high on both side as Finnish bombers and German Stuka dive-bombers pounded the Soviet formations. The Soviet air forces also attacked, and the bombers of the 276^th Bomber Division hit the headquarters of the Panssaridivisoona. On this same day Oesch ordered his forces to fall back to the line of linking Vakkila, Ihantalajärvi, Kokkoselkä and Noskuanselkä, still within the 'VKT-linja', but they became caught in a new Soviet offensive.

The hardest and the worst day for the Finns during the whole battle was 29 June, when defeat was not far off, but the Finns finally managed to restore the line after very bloody fighting. On the following day, the Finns retreated from Tali.

The heaviest fighting took place on 1 and 2 July, when the Finns lost some 800 men per day. The Finnish concentration of artillery fire that followed was the heaviest in the country’s military history, and based on the fire correction method devised by Tykistönkenraali Vilho Petter Nenonen, an artillery specialist, which enabled easy fire correction and rapid changes between targets. On the critical Ihantala sector of the battle the Finnish defenders achieved a superb concentration of fire and smashed the advancing Soviet spearhead. The Finnish fire-control system made it possible for as many as 21 batteries (250 guns) to undertake the simultaneous engagement of a single target even though the fire controller did not need to be aware of the location of individual batteries to guide their fire. By this time the Finns had concentrated half of their entire artillery capability in the area, along with the Panssaridivisoona (with StuG III assault guns as its primary weapon) and the 303^rd Sturmgeschützbrigade. Another factor which now aided the Finns was that they finally had the new German anti-tank weapons that have previously been kept in reserve.

On 2 July the Finns intercepted a radio message indicating that the 63^rd Division and 30^th Tank Brigade were to launch an attack at 04.00 on 3 July. Two minutes before the planned Soviet attack, 40 Finnish and 40 German bombers bombed the Soviet troops, and 250 pieces of artillery fired 4,000 shells into the area. From 06.00 on the same day, 200 Soviet warplanes and massed infantry attacked the Finnish line, but by 19.00 the Finns had restored their line.

On 6 July the Soviets enjoyed some success despite the fact that the 6^th Division had 18 artillery battalions and one heavy battery to support its defence. The Soviets were thrown back on the following day, however, and their counterattacks at 13.30 and 19.00 on that day both failed.

By 7 July the focus of the Soviet attacks was already moving to the Vuoksi area, and the Soviets now began to move their best troops to the Narva front in Estonia, to fight the Germans and the Estonians. From 9 July the Soviets no longer attempted to break through, but some fighting nonetheless continued.

The Finns estimated that the Soviets lost about 300 tanks in the Tali-Ihantala fighting, mainly to air attacks and close defence weapons, and also between 120 and 280 aircraft. The Finns admitted to the loss of 8,561 men killed, wounded or missing. Based on the daily and 10-day summary casualty reports of their 21^st Army, the Soviets reported their losses as between 18,000 and 22,000 killed or wounded.

Together with other Finnish tactical victories achieved during this period, the Battle of Tali-Ihantala served to convince the Soviet leadership that the complete military defeat of Finland would be costly beyond the benefits likely to be achieved: the Soviet forces had concentrated what was thought to be an overwhelming superiority of force against Finland, and had failed. The Battle of Tali-Ihantala was possibly the single most important battle of the 'Jatkosota' and largely determined the war’s outcome in permitting the Finns to conclude the war on relatively favourable terms. The campaign in the Karelian isthmus during the summer of 1944 paved the way to peace talks between Finland and the USSR, and thus to Finland’s continued existence as an autonomous and independent nation.

The Battle of Tali-Ihantala did not take place in isolation, though, and contemporary operations should also be noted as factors that led to the peace negotiations. From 4 July, for instance, elements of the General Leytenant Ivan T. Korotnikov’s 59^th Army attacked across the islands of the Bay of Viipuri, but its attack to the mainland was thrown back by the German forces of Generalmajor Hero Breusing’s 122^nd Division of General Dr Franz Beyer’s V Corps on 10 July.

Following the Soviet failure at Tali on 3 July, the 23^rd Army attempted a crossing of the Vuoksi river on the following day at Vuosalmi, but was not able to expand its initial bridgehead, despite the fact that it had three divisions there against the 2^nd Divisioona. The Soviet breakthrough attempts continued in this area until 21 July. In addition to the defensive victory gained at Tali-Ihantala, the front line held fast at Kivisilta and Tienhaara to the north of the Bay of Viipuri, and at Vuosalmi on the bank of the Vuoksi river. The Finns gained other defensive victories at the Bay of Viipuri and on the north-eastern side of the Lake Ladoga, and in the Battle of Ilomantsi the Finns were able to encircle two Soviet divisions.

On 12 July the Soviet troops were ordered to cease their attempts to advance and to dig in. Soon, Finnish scouts noticed trains with empty trucks moving toward Viipuri to remove troops away from the Finnish front for redeployment as part of the great 'Bagration' offensive that had started in Belorussia and Poland on 22 June. The eventual ceasefire between Finland and the USSR began at 07.00 on 4 September 1944, although for the following 24 hours the Soviet forces did not comply with it.