He was awarded the Nobel Peace Prize in 1990 in acknowledgment of his influence in defusing East-West tensions.
Born into a peasant family in the agrarian district of Stavropol, Gorbachov was a farm worker in his youth. Being clever and ambitious, however, he went to Moscow University in 1953 to study law, returning to Stavropol after graduating to begin his political career. He became head of the Komsomol (Young Communist League), took charge of collective farms in the area, and in 1970 became first secretary of the Communist Party in Stavropol.

In 1978 he moved to Moscow to become agriculture secretary of the central committee of the Soviet Communist Party (CPSV), in which position he introduced the contract system for team payment by results; two years later he was elected a full member of the Politburo. In the four years before he succeeded Konstantin Chernenko as general secretary Gorbachov acquired responsibility for economic, ideological, and party matters as well as for some aspects of foreign affairs. In 1984 he made an official visit to London, where he was well received.

A dynamic and forceful character, as general secretary he embarked on a radical programme of economic and social reform, summarized as glasnost (openness) and perestroika (restructuring). Political changes introduced under the programme included the toleration of dissident views, with the establishment in 1989 of a Congress of People's Deputies to enable such views to be heard, and culminated in 1990 in the Communist Party losing its monopoly of power.

Social reforms included religious toleration, increased artistic freedom, and easing of travel restrictions. In foreign policy, Gorbachov agreed major new arms-limitation treaties (1987 and 1990) with the USA, effectively bringing about the end of the Cold War. Hailed as a hero in the West, at home he was regarded with hostility by both conservatives within the Communist Party and by reformers who considered the pace of liberalization too slow.

In 1989 he acquiesced in the dismantling of communist regimes in eastern Europe, culminating in the reunification of Germany in 1990. At the same time, however, he steadfastly opposed the break-up of the Soviet Union into its constituent republics, using the army to suppress nationalists in such dissident regions as Lithuania. His attempts to transform the Soviet Union's outdated industrial base by encouraging a more free-market approach seem only to have exacerbated the country's economic problems, undermining any remaining support for him among ordinary people.

In the face of gathering opposition from critics, especially Boris Yeltsin, he pushed through legislation in 1990 greatly strengthening his personal powers as president. Signs that Gorbachov might be backing away from the principles of glasnost caused some disquiet in the West and prompted speculation about his continuing political survival. These fears proved well-founded in August 1991 when, on the eve of the signing of a new Union treaty, he was overthrown in a coup led by hardliners fearing the break-up of the Soviet Union.

The coup collapsed after several days, largely through the open resistance of Boris Yeltsin, enabling Gorbachov to return from a brief exile in the Crimea, where he had been held under house arrest. To remain in power, he was obliged to agree to a new political understanding with Yeltsin and to dissociate himself from the discredited Communist Party, resigning as its general secretary.

He went on to promise de facto independence to the Baltic republics, new parliamentary elections, and more rapid progress to a market economy, while still hoping to preserve the Soviet Union as a union of sovereign states with a single army and a single economy. He resigned in December 1991 after failing to prevent the break-up of the Soviet Union. In 1996 he challenged his successor Yeltsin in the presidential elections but received less than one per cent of the popular vote.