Shumshu was the site of the first major Soviet battle in the 1945 Kuril Islands campaign.
The Battle of Shumshu began on August 18, 1945, when Soviet forces landed on the island in the northern Kurils. Japanese troops resisted with artillery, tanks, and defensive positions, making the battle unusually intense for a campaign launched after Japan had announced its surrender.
Japanese forces on Shumshu, Paramushiro, and Onekotan signed an unconditional surrender agreement on August 19, although fighting on Shumshu continued in places until August 23. The battle is often described as arguably the last major battle of World War II.
The Soviet Union continued occupying the Kuril chain after Shumshu. Soviet forces completed their occupation of the islands on September 5, 1945. Shumshu is sometimes confused with Hokkaido because Soviet planners considered a possible invasion of Japan’s northern home island, but no Soviet invasion of Hokkaido took place.