Complex sentence: He governed the Soviet Union as dictator from the mid- 1920s until his death in 1953, serving as Premier of the Soviet Union from 1941 to 1953 and as General Secretary of the Central Committee of the Communist Party of the Soviet Union from 1922 to 1952.
Split into simpler sentences: He governed the Soviet Union as dictator from the mid- 1920s until his death in 1953. In this capacity, he served as the Premier of the Soviet Union from 1941 to 1953 and as General Secretary of the Central Committee of the Communist Party of the Soviet Union from 1922 to 1952.