The 'Tallinn Offensive Operation' was the second of the four Soviet sub-operations together constituting the 'Baltic Strategic Offensive Operation' and culminating in the capture of Tallinn (Reval in German) in Estonia (17/26 September 1944).

The Soviet forces had advanced toward the Baltic Sea coast at the end of the 'Belorussian Strategic Offensive Operation', otherwise known as 'Bagration', of June/August 1944 against Generaloberst Johannes Friessner’s (from 25 July Generaloberst Ferdinand Schörner’s) Heeresgruppe 'Nord'. In the north, the attacks of Marshal Sovetskogo Soyuza Leonid A. Govorov’s Leningrad Front had pushed Heeresgruppe 'Nord' into the area to the west of Lake Peipus, resulting in a series of defensive undertakings by the German forces in the so-called Battle of Narva.

The 'Baltic Strategic Offensive Operation', of which the 'Tallinn Offensive Operation' was a component, was designed to complete the elimination of the Baltic coast positions of Heeresgruppe 'Nord', and for this purpose the Soviets used Govorov’s Leningrad Front (General Leytenant Filipp N. Starikov’s 8^th Army and General Leytenant Ivan I. Fedyuninsky’s 2^nd Shock Army) and General Ivan I. Maslennikov’s 3^rd Baltic Front (General Leytenant Nikanor D. Zakhvatayev’s 1^st Shock Army, General Leytenant Vladimir P. Sviridov’s 42^nd Army, General Leytenant Sergei V. Roginsky’s 54^th Army and General Leytenant Vladimir Z. Romanovsky’s 67^th Army). Schörner’s Heeresgruppe 'Nord' had elements of General Ehrenfried-Oskar Boege’s 18^th Army in the south and General Anton Grasser’s Armeeabteilung 'Narwa' (SS-Obergruppenführer und General der Waffen-SS Felix Steiner’s III SS Panzerkorps [germanisch] and Generalleutnant Wilhelm Hasse’s II Corps) in the north.

As the first of the four major sub-components of the 'Baltic Strategic Offensive Operation', the 'Riga Offensive Operation' began on 14 September with a major assault by all three Soviet Baltic fronts. The north-east wing of this force, Maslennikov’s 3^rd Baltic Front, directed its greatest power against General Hans Gollnick’s XXVIII Corps of the 18^th Army, whose front began to collapse in the vicinity of Tartu (Dorpat in German), and Schörner was able to stabilise the 18^th Army's lines, albeit only temporarily, at Võrtsjärv by rushing every available unit into the defence. The Armeeabteilung 'Narwa', the most northern element of Heeresgruppe 'Nord, was now in imminent danger of encirclement by the Gulf of Finland, the Baltic Sea, Fedyuninsky’s 2^nd Shock Army and Starikov’s 8^th Army in the event that the last broke through to the Gulf of Riga. The 2^nd Shock Army in fact broke through to take Tartu on 17 September.

The 18^th Army was similarly threatened in the south. Holding an extended front in the face of intense Soviet pressure, Schörner decided to evacuate all his forces from Estonia in 'Aster' (ii).

The object of the Soviet forces was now to complete the seizure of Estonia and its capital, Tallinn. The Stavka hoped that a rapid breakthrough at the Emajõgi sector of the front would open a path for the armoured units to advance to the north, thus dividing the Armeeabteilung 'Narwa' from the rest of Heeresgruppe 'Nord'. The Soviet command presumed that the main direction of retreat for the German forces would be in the direction of Tallinn, and concentrated their forces in that region in an attempt to block the roads.

Heeresgruppe 'Nord' had already considered abandoning Estonia in February 1944, during the 'Kingisepp-Gdov Offensive Operation' (1 February/1 March 1944), a subcomponent of the 'Leningrad-Novgorod Strategic Offensive Operation' (14 January/1 March 1944). German commanders appreciated that many formations and units would thereby have been freed as a result in the changes and shortening of the front, but the commanders' early hopes were stymied by Adolf Hitler’s insistence that the Narva front had still to be held in order to retain command of the southern coast of the Gulf of Finland in order to ease the situation in Finland, to keep the Soviet Baltic Fleet trapped at the eastern end of the gulf, and to retain the economically and militarily important oil shale reserves and oil shale industry in the Ida-Viru area.

The exit of Finland from the war on 3 September finally provided the political impetus for the abandonment of Estonia. On the following day, Generaloberst Heinz Guderian, the Oberkommando des Heeres’s chief-of-staff, suggested that it would no longer be feasible to attempt to hold the Ostland (German-oocupied Lithuania, Latvia and Estonia), and therefore ordered an evacuation operation, codenamed 'Königsberg', to be planned. However, Hitler ordered that, regardless of the cost, the Ostland must not be yielded as to do so would provide support to those Finns who did not favour the new course of the government, and would influence Sweden to maintain its current foreign policy. Even so, Guderian ordered that the 'Königsberg' plan nonetheless be secretly started. On the next day, Generalmajor Oldwig Otto von Natzmer, the chief-of-staff of Heeresgruppe 'Nord', visited the headquarters of the Armeeabteilung 'Narwa' to discuss details of the evacuation, and on 11 September the evacuation of Estonia was the subject of a lengthy discussion at the headquarters of Heeresgruppe 'Nord'. On 15 September, Schörner asked Guderian to convince Hitler to order the evacuation of German troops from the continental part of Estonia in 'Aster' (ii). Schörner emphasised that although the front was still holding, delaying the order would mean the units in Estonia would be trapped, and Hitler concurred on 16 September.

For 'Aster' (ii), the main strength of the Armeeabteilung 'Narwa' was to withdraw mainly through Viljandi and Pärnu toward Riga. In order that this could be achieved, it was essential that Hasse’s II Corps on the Emajõgi sector of the front and Gollnick’s XXVIII Corps on the Väike Emajõgi sector keep the front line stable until the Armeeabteilung 'Narwa' had passed behind them. The operation was scheduled to start on 19 September, and the retreat was to be a staged retirement through several lines of resistance. The withdrawal was to be backed mainly by formations and units consisting of ethnic Estonians who, the Germans reckoned, would not in any event wish to leave Estonia.

A naval force under the command of Vizeadmiral Theodor Burchardi began to evacuate elements of the German formations along with some civilians on 17 September, and the headquarters prepared a detailed plan to fall back from its location on the Narva front during the night of 18/19 September.

Various Estonian units, drawing their manpower largely from men who had deserted from SS-Brigadeführer und Generalmajor der Waffen-SS Franz Augsberger’s 20^th Waffen-Grenadierdivision der SS (estnisch Nr 1), Omakaitse home guard militia, border defence and auxiliary police battalions, had no general plan, but were motivated largely to defend the independence of Estonia.

By the beginning of the 'Tallinn Offensive Operation' on 17 September along the Emajõgi front, the II Corps had been reduced to a real strength of little more than a 4,600 men, and with this was intended to check the 140,000 men of the 2^nd Shock Army. While the II Corps had almost no armoured forces, the 3^rd Baltic Front deployed 300 armoured vehicles. For the start of the offensive, the Soviets had deployed 2,569 pieces of artillery along the 56-mile (90-km) front, pitting 220 pieces per mile (137 pieces per km) against the German forces' essentially non-existent artillery strength. The 15,000-man III SS Panzerkorps faced the 55,000-man Soviet 8^th Army on the Narva front. The pro-independence Estonian troops totalled some 2,000 men.

The 3^rd Baltic Front began its offensive during the early morning of 17 September. After subjecting the II Corps to a barrage of 132,500 shells, the three leading Soviet infantry corps crossed the Emajõgi river along the 15.5-mile (25-km) section of the front to the east of Tartu and breached the German defences. The 2^nd Shock Army forced its way through to the German divisional headquarters and artillery positions. Only SS-Standartenführer Alfons Rebane’s Kampfgruppe 'Rebane' of the 20^th Waffen-Grenadierdivision der SS, located near Tartu, managed to hold its front, though only at the cost of heavy losses. The Armeeabteilung 'Narwa' and the XXVIII Corps, the most northerly elements of Heeresgruppe 'Nord', were now in imminent danger of encirclement and destruction, and Schörner ordered the II Corps to abandon the defence of the Emajõgi river and move as rapidly as it could around the northern tip of Lake Võrtsjärv into northern Latvia.

Six Estonian border defence regiments, the 113^th Sicherungsregiment, and the remnants of the 20^th Waffen Grenadierdivision der SS retreating from the most distant part of the Narva front in the Krivasoo swamp area were blocked by the advance units of General Leytenant Lembit Pärn’s VIII Estonian Corps and destroyed in fighting at Porkuni and Avinurme on 20 and 21 September respectively. The Estonians of this Soviet corps killed all their compatriots who had been taken prisoner at Porkuni and also the wounded sheltering in the parish church at Avinurme.

Even so, the defence of these units bought the time needed by the Armeeabteilung 'Narwa' to escape from Estonia as the III SS Panzerkorps and Generalleutnant Hellmuth Reymenn’s 11^th Division abandoned their positions, undetected by the 8^th Army, which therefore caused few casualties and took only a few prisoners as it started to advance during the early part of the morning, took Jõhvi, and by the evening of the same day had reached the line connecting Toila and Kurtna via Jõhvi. During the night of 20 September, the headquarters of the III SS Panzerkorps was near Pärnu on the south-west coast of Estonia, alongside SS-Brigadeführer und Generalmajor Jürgen Wagner’s SS Freiwilligen-Panzergrenadierbrigade 'Nederland', SS-Brigadeführer und Generalmajor der Waffen-SS Joachim Ziegler’s 11^th SS Panzergrenadierdivision 'Nordland' and the 11^th Division. The 11^th SS Panzergrenadierdivision 'Nordland' and 11^th Division were then sent to Latvia to become part of the 16^th Army, while the SS Freiwilligen-Panzergrenadierbrigade 'Nederland' remained to organise the defence of Pärnu. On 23 September, the brigade destroyed Pärnu’s harbour and fell back toward Latvia, and on the following day, near Ikla on the Estonian/Latvian border the brigade’s rearguard fought the unit’s last battle on Estonian soil, in the process destroying 12 to 15 Soviet tanks.

Military personnel, the wounded, industries, prisoners and civilians were evacuated mostly by sea under the supervision of Burchardi, who was primarily responsible for securing the evacuations from Tallinn and Paldiski. For this purpose, he had under his command the vessels of Fregattenkapitän Erich Brauneis’s 24^th Landungs-Flottille, Korvettenkapitän Christian Petersen’s 14^th Sicherungs-Flottille, Kapitänleutnant Prater’s 31^st Minensuch-Flottille, Korvettenkapitän von Kleist’s 5^th Sicherungs-Flotille and Kapitänleutnant Hoff’s 1^st Räumboots-Flottille, with a total of about 50 small warships, launches, escort ships and other vessels. Within six days, some 50,000 troops, 20,000 civilians, 1,000 prisoners of war and 30,000 tons of equipment and supplies had been removed from Estonia, 38,000 of the military personnel by sea. The worst loss in the course of the sea evacuation was that of the hospital ship Moero, which was sunk with the loss of 637 of the 1,155 persons on board. Despite the fact that the time for evacuation was much shorter than had been planned, the sea evacuation was seen as a major success, with only 0.9% of the evacuees killed.

On 18 September, the provisional government formed in Tallinn by the National Committee of the Republic of Estonia declared the independence of Estonia, and Estonian military units clashed with German troops in Tallinn, seizing the state offices at Toompea. The government appealed to the USSR to recognise the independence of the republic.

By the time that the vanguard of the Leningrad Front arrived at Tallinn early on 22 September, German troops had to all intents and purposes abandoned the city, whose streets were empty. The last German unit to leave Tallinn before the arrival of the Soviet forces was the 531^st Marine Artillerieabteilung, whose men destroyed all fixed artillery and armaments, special equipment, guns which could not be evacuated, ammunition, the telephone exchange, the radio broadcast facility, locomotives and railway wagons, and the railway lines before they embarked. Tallinn’s power plant was subjected to the fire of ships at sea, and the harbour of the old city was destroyed.

The retreating German formations and units had no combat contact with the Soviet forces in Tallinn. The Estonian government had meanwhile failed to concentrate the Estonian soldiers retreating from the Narva and Emajõgi fronts, as these units were scattered and mixed with the German detachments withdrawing towards Latvia, and therefore lacked the military strength with which to attempt a repulse of the Soviet forces in the Tallinn area, which was held by a modest number of units commanded by Rear Admiral Johan Pitka.

Men of the Leningrad Front entered and quickly seized control of Tallinn on 22 September, and Jüri Uluots, the acting president of Estonia, was evacuated to Sweden. In the following days, several pro-independence Estonian battle groups attacked the Soviet troops in Harju and Lääne area, but were soundly defeated.

The German evacuation had been carried out in an orderly fashion. The plan of Heeresgruppe 'Nord' worked very well, and both the Soviets and the German high command were both surprised and impressed by the speed of the evacuation. By 24 September the Soviets had demolished the harbour at Haapsaalu, just to the east of the Moonsund archipelago, and the Germans evacuated Vormsi island, just off the coast, on the following day. Starikov’s 8^th Army went on to take the remaining islands off the Estonian coast (Moonsund archipelago) in the 'Moonzund Landing Operation', and in overall terms the 'Baltic Strategic Offensive Operation' had resulted in the expulsion of German forces from Estonia, Lithuania and a large part of Latvia.

The remainder of the 'Baltic Strategic Offensive Operation' saw Heeresgruppe 'Nord' driven into the Kurland peninsula, where it remained until the end of the war.