The Soviet Union shaped the history of the 20th century like no other country except the USA. At the height of its development, in the 1960s and early 1970s, it could rightly be considered the second superpower, having also captured important strongholds in the fiercely contested "Third World." This presentation provides an overview of the key phases of development, turning points, and breaks in Soviet history. The research section particularly focuses on Stalinism, "developed socialism" under Brezhnev, and the causes of the collapse.