Kirill Trofimovich Mazurov was a Soviet partisan, politician, and one of the leaders of the Belarusian resistance during World War II who governed the Byelorussian Soviet Socialist Republic as First Secretary of the Communist Party of Byelorussia from 1956 until 1965, when he became a member of the Politburo of the CPSU.

The Communist Party of the Soviet Union (CPSU), at some points known as the Russian Communist Party, All-Union Communist Party and Bolshevik Party, and sometimes referred to as the Soviet Communist Party (SCP), was the founding and ruling political party of the Soviet Union. The CPSU was the sole governing party of the Soviet Union until 1990 when the Congress of People's Deputies modified Article 6 of the 1977 Soviet Constitution, which had previously granted the CPSU a monopoly over the political system. The party's main ideology was Marxism–Leninism.