Many people fled from Königsberg ahead of the Red Army 's advance after October 1944 , particularly after word spread of the Soviet atrocities at Nemmersdorf . In early 1945 , Soviet forces , under the command of the Polish-born Soviet Marshal Konstantin Rokossovsky , besieged the city that Hitler had envisaged as the home for a museum holding all the Germans had ' found in Russia ' . In Operation Samland , General Baghramyan 's 1st Baltic Front , now known as the Samland Group , captured Königsberg in April . Although Hitler had declared Königsberg an " invincible bastion of German spirit " , the Soviets captured the city after a three-month-long siege . A temporary German breakout had allowed some of the remaining civilians to escape via train and naval evacuation from the nearby port of Pillau . Königsberg , which had been declared a " fortress " ( '' Festung '' ) by the Germans , was fanatically defended
Nemmersdorf
Nemmersdorf massacre
Königsberg