invade the Soviet Union
June 22, 1941–November 1941 Nazi Germany and its Axis partners (except Bulgaria) invade the Soviet Union. Finland, seeking redress for the territorial losses in the armistice concluding the so-called Winter War, agrees to participate in the invasion. The Germans quickly overrun the Baltic states and, joined by the Finns, lay siege to Leningrad (St. Petersburg) by September. In the center, the Germans capture Smolensk in early August and drive on Moscow by October. In the south, German and Romanian troops capture Kiev (Kyiv) in September and capture Rostov on the Don River in November.