The Battle of Königsberg, also known as the Königsberg offensive, was one of the last operations of the East Prussian offensive during World War II. In four days of urban warfare, Soviet forces of the 1st Baltic Front and the 3rd Belorussian Front captured the city of Königsberg, present day Kaliningrad, Russia. The siege started in late January 1945 when the Soviets initially surrounded the city. Heavy fighting took place for control of overland connection between Königsberg and the port of Pillau, but by March 1945 Königsberg was hundreds of kilometres behind the main front line in the eastern front. The battle ended when the German garrison surrendered to the Soviets on 9 April after a three-day assault made their position untenable.
The East Prussian offensive was planned by the Soviet Stavka to prevent flank attacks on the armies rushing towards Berlin. Indeed, East Prussia held numerous troops that could be used for this. During initial Stavka planning, Joseph Stalin ordered Marshal Konstantin Rokossovsky to annihilate the Wehrmacht forces trapped there.
On 13 January 1945, almost 1,500,000 troops supported by several thousand tanks and aircraft of the 3rd Belorussian Front (11th Guards, 39th, 43rd, 50th, 1st Air, 3rd Air, 4th Air, and 15th Air Armies) entered East Prussia, which had been transformed into a gigantic web of fortifications, defensive lines and minefields. Progress was initially very slow. Red Army troops only advanced 1.5 kilometers the first day, through only three defensive lines. In five days, taking heavy losses, Soviet troops advanced only 20 kilometers and were unable to break through German lines into open ground.
The initial setback did not last and on 24 January Soviet advance forces reached the shores of the Vistula Lagoon (part of the Baltic Sea), cutting off the German forces in East Prussia from a direct connection with Germany, forcing the Germans to supply the surrounded forces by sea. This operation was accomplished by the 1st Baltic Front under the command of Ivan Bagramyan.
On 25 January 1945, in a tacit acknowledgement that German forces in East Prussia and the Courland Pocket were far behind the new front line, Hitler renamed three army groups. Army Group North became Army Group Courland; Army Group Centre (the army group surrounded in the Königsberg pocket) became Army Group North and Army Group A became Army Group Centre.
Those forces, now redesignated as Army Group North, were compressed by further Soviet attacks into three pockets: one around Königsberg, one on the adjacent Sambia Peninsula, and one on the coast of the Vistula Lagoon to the south-west (the Heiligenbeil Pocket).
By late January 1945 the 3rd Belorussian Front had surrounded Königsberg on the landward side, severing the road down the Samland peninsula to the port of Pillau, and trapping the 3rd Panzer Army and approximately 200,000 civilians in the city. The civilian provisions were so meagre that civilians were faced with three bleak alternatives:
Remain in the city and starve – rations were cut during the siege to 180 grams of bread a day
Cross the front lines and leave themselves at the mercies of the Soviets
Cross the ice of the Vistula Lagoon to Pillau in hope of finding a place on an evacuation ship
Hundreds chose to cross the front line, but about 2,000 women and children a day chose to cross the ice on foot to Pillau. On his return from a visit to Berlin, Erich Koch, the Gauleiter of East Prussia, chose to stay in the relative safety of Pillau to organize the evacuation rather than return to Königsberg. The first evacuation steamer from Pillau carrying 1,800 civilians and 1,200 casualties reached safety on the 28 January.
The only remaining way to escape Königsberg to Pillau was through Metgethen, a strategically important quarter. On the 29th, it was attacked by the Red Army and completely overrun.
Throughout February, there was desperate fighting as the Germans tried to maintain the narrow connection between Königsberg and Samland. For a time, Soviet troops were successful in severing that connection and cutting the city off completely.
On 19 February the 3rd Panzer Army and the 4th Army attacked from the direction of Pillau, managing to force open a corridor from Königsberg to Pillau. Led by a captured Soviet T-34 tank, this attack was spearheaded by the 1st Infantry Division from Königsberg, intended to link with General Hans Gollnick's XXVIII Corps, which held parts of the Samland peninsula, including the vital port of Pillau. Capturing the town of Metgethen, the unit opened the way for the 5th Panzer Division to join with Gollnick's forces near the town of Gross Heydekrug the next day. This action solidified the German defence of the area until April, re-opening the land route from Königsberg to Pillau, through which supplies could be delivered by ship and the wounded and refugees could be evacuated. This month-long battle is sometimes called the First Siege of Königsberg.
In March the situation had stabilized – by now, the main front line had moved hundreds of kilometres to the west, and capturing the city took a much lower priority for the Soviets. Even so, the garrison was intact and showed no signs of surrender. Eventually, the Soviet command decided to capture the city by assault rather than a siege.
Assaulting Königsberg was not to be an easy task. Garrisoned inside the city were five divisions (61st, 69th and 367th Infantry Divisions, 548th and 561st Volksgrenadier Divisions), for a total of 130,000 troops, along with impressive defensive positions constructed in 1888 that included fifteen forts interconnected by tunnels with integrated accommodations for the troops, and designed to withstand the bombardment of super-guns being designed in that era following the siege of Paris (1870–1871). The Germans still held a narrow land connection to the adjacent German pocket on the Samland peninsula. The capture of the city necessitated this frantically shielded connection be separated. The German troops on the peninsula, the so-called Samland Group, could be expected to stage counter-attacks to prevent this from happening.
Königsberg was, according to Winston Churchill, "a modernised heavily defended fortress". Three concentric rings of fortifications surrounded the city: the outer ring of defences reinforced by 12 forts outside the town, the middle ring in the outskirts and the inner city, a single fortress of anti-tank defences, barricades and landmines, along with several other forts.
In order to face such defensive power, the Soviet command planned to heavily rely on aviation and artillery support, with densities reaching 250 guns per kilometre in some areas. The German troops were also subjected to propaganda, explaining that their resistance was futile, and that the front line was far behind them — that they were trapped in a "pocket" and that it would be best to surrender. However, this propaganda had little to no effect.