Leonid Ilyich Brezhnev (/ˈbrɛʒnɛf/; Russian: Леони́д Ильи́ч Бре́жнев; IPA: [lʲɪɐˈnʲid ɪˈlʲjitɕ ˈbrʲɛʐnʲɪf] ( listen); Ukrainian: Леоні́д Іллі́ч Бре́жнєв, 19 December 1906 (O.S. 6 December) – 10 November 1982) was the General Secretary of the Central Committee (CC) of the Communist Party of the Soviet Union (CPSU), presiding over the country from 1964 until his death in 1982. His eighteen-year term as General Secretary was second only to that of Joseph Stalin in duration. During Brezhnev's rule, the global influence of the Soviet Union grew dramatically, in part because of the expansion of the Soviet military during this time. His tenure as leader was marked by the beginning of an era of economic and social stagnation in the Soviet Union.
Brezhnev was born in Kamenskoye (now Kamianske, Ukraine) into a Russian worker's family in 1906. After graduating from the Dniprodzerzhynsk Metallurgical Technicum, he became a metallurgical engineer in the iron and steel industry, in Ukraine. He joined Komsomol in 1923, and in 1929 became an active member of the CPSU. He was drafted into immediate military service during World War II and left the army in 1946 with the rank of major general. In 1952 Brezhnev became a member of the Central Committee, and during 1964, Brezhnev succeeded Nikita Khrushchev as First Secretary, while Alexei Kosygin succeeded Khrushchev in his post as Soviet premier.
As a leader, Brezhnev took care to consult his colleagues before acting, but his attempt to govern without meaningful economic reforms led to a national decline by the mid-1970s, a period referred to as the Era of Stagnation. A significant increase in military expenditure, which by the time of Brezhnev's death stood at approximately 12.5% of the country's GNP, and an aging and ineffective leadership set the stage for a dwindling GNP compared to Western nations. While at the helm of the USSR, Brezhnev pushed for détente between the Eastern and Western countries. At the same time he presided over the Warsaw Pact invasion of Czechoslovakia to stop the Prague Spring, and he sent the Soviet military to Afghanistan in an attempt to save the fragile regime, which was fighting a war against the CIA-backed mujahideen. However, in December 1981 he decided not to militarily intervene in Poland, instead allowing the country's government to impose martial law, and effectively marking the end of the Brezhnev Doctrine.
After years of declining health, Brezhnev died on 10 November 1982 and was quickly succeeded in his post as General Secretary by Yuri Andropov. Brezhnev had fostered a cult of personality, although not nearly to the same degree as Stalin. Mikhail Gorbachev, who would lead the USSR from 1985 to 1991, denounced his legacy and drove the process of liberalisation of the Soviet Union. In spite of this, opinion polls in Russia show Brezhnev to be the most popular Russian leader of the 20th century.