The historical figure known for leading the Soviet Union during World War II was Joseph Stalin. He became the General Secretary of the Communist Party of the Soviet Union in the 1920s and consolidated power throughout the 1930s. During World War II, Stalin played a crucial role, overseeing the Soviet Union's extensive military efforts against Nazi Germany after the invasion in 1941. Under his leadership, the Red Army pushed back German forces, leading to significant victories at battles such as Stalingrad and Kursk. Stalin's wartime leadership not only shaped the outcome of the war in Europe but also established the Soviet Union as a central power in post-war geopolitics.