chief political leader of the Soviet Union from February 1984 until his death in 1985.

Born to a Russian peasant family in the Yeniseysk region of Siberia, Chernenko joined the Communist Party in 1931. Trained as a party propagandist, he held several administrative posts before becoming head of agitation and propaganda (agitprop) in Moldavia (1948–56), where he was first noticed by Leonid Brezhnev (Brezhnev, Leonid Ilich) and brought to Moscow to head a similar department for the party's Central Committee (1956–60). When Brezhnev took over the party in 1964, he made Chernenko his chief of staff. Chernenko was a full member of the Central Committee from 1971 and of the Politburo from 1977.

An old-line conservative, Chernenko traveled extensively with Brezhnev and was considered his aide, confidant, and, by some observers, his heir apparent. After Brezhnev's death, however, he was unable to rally a majority of the party factions behind his candidacy to be head of the party and lost out to Yury V. Andropov (Andropov, Yury Vladimirovich), the former KGB chief, who became general secretary on Nov. 12, 1982. However, Andropov had become mortally ill by the following August, and after his death six months later, Chernenko succeeded him as general secretary of the Communist Party of the Soviet Union on Feb. 13, 1984. On April 12 he became chairman of the Presidium of the Supreme Soviet.

Like his predecessor, Chernenko began showing signs of deteriorating health shortly after taking office. His frequent absences from official functions because of illness left little doubt that his election had been an interim measure, and upon his death he was succeeded by Mikhail S. Gorbachev.