After Stalin's death in 1953, the Soviet Union entered a period of collective leadership as there was no clear successor. Khrushchev, Malenkov, Molotov, and Bulganin emerged as the main contenders for power. Over time, through political maneuvering and outmaneuvering his rivals, Khrushchev was able to consolidate power and become the sole leader of the Soviet Union by 1958, emerging as both First Secretary of the Communist Party and Chairman of the Council of Ministers.