Secretariat of the Communist Party of the Soviet Union the CPSU, who was also a Politburo member, was the leader of the Secretariat and of the Party. Dual membership in the Secretariat and the Politburo was in practice reserved for two or three very senior members of the Soviet leadership, and in the post-Stalin era (after March 1953) was a stepping-stone to ultimate power. The last five Soviet leaders (Nikita Khrushchev, Leonid Brezhnev, Yuri Andropov, Konstantin Chernenko and Mikhail Gorbachev) were all senior Secretaries before becoming First or General Secretaries. Additionally, Georgy Malenkov was briefly reckoned as the leader of the Party for a week after Stalin's death by
Polish prisoners-of-war in the Soviet Union after 1939 the Soviet Union (although there were notable exceptions, see Trial of the Sixteen); most were transferred to the Polish communist security forces and prisons, or enlisted in the Berling Army. Polish prisoners-of-war in the Soviet Union after 1939 As a result of the Soviet invasion of Poland in 1939, hundreds of thousands of Polish soldiers became prisoners of war in the Soviet Union. Many of them were executed; over 20,000 Polish military personnel and civilians perished in the Katyn massacre. On September 17, 1939, the Red Army invaded the territory of Poland from the east. The invasion took place while