Following the end of the war , under border changes promulgated at the Potsdam Conference in 1945 , the northern part of East Prussia became a part of the Soviet Union , including Gumbinnen . The town was renamed Gusev , in honour of a Red Army captain , Sergei Ivanovich Gusev , who was killed in action near Gumbinnen in January 1945 , and was posthumously given the award of Hero of the Soviet Union on April 19 , 1945
Potsdam Conference
Potsdam Conference
Gusev, Kaliningrad Oblast