Mikhail Sergeyevich Gorbachev (born March 2, 1931) is a Russian and former Soviet politician.

The eighth and last leader of the Soviet Union, he is the general secretary of the Communist Party of the Soviet Union from 1985 until 1991.

He is also the country's head of state from 1988 until 1991, serving as the chairman of the Presidium of the Supreme Soviet from 1988 to 1989, chairman of the Supreme Soviet from 1989 to 1990, and president of the Soviet Union from 1990 to 1991.

Ideologically, he had initially adhered to Marxism–Leninism although by the early 1990s had moved toward social democracy.

Of mixed Russian and Ukrainian heritage, Gorbachev was born in Privolnoye, Stavropol Krai, to a poor peasant family.

Growing up under the rule of Joseph Stalin, in his youth he operates combine harvesters on a collective farm before joining the Communist Party, which at this time governs the Soviet Union as a one-party state according to Marxist-Leninist doctrine.

While studying at Moscow State University, he marries fellow student Raisa Titarenko in 1953 prior to receiving his law degree in 1955.

Moving to Stavropol, he works for the Komsomol youth organization and, after Stalin's death, becomes a keen proponent of the de-Stalinization reforms of Soviet leader Nikita Khrushchev.

He is appointed the First Party Secretary of the Stavropol Regional Committee in 1970, in which position he oversees construction of the Great Stavropol Canal.

In 1978 he returns to Moscow to become a Secretary of the party's Central Committee and in 1979 joins its governing Politburo.

Within three years of the death of Soviet leader Leonid Brezhnev, following the brief regimes of Yuri Andropov and Konstantin Chernenko, the Politburo elects Gorbachev as General Secretary, the de facto head of government, in 1985.

Although committed to preserving the Soviet state and to its socialist ideals, Gorbachev believes significant reform is necessary, particularly after the 1986 Chernobyl disaster.

He withdraws from the Soviet–Afghan War and embarks on summits with United States President Ronald Reagan to limit nuclear weapons and end the Cold War.

Domestically, his policy of glasnost ("openness") allows for enhanced freedom of speech and press, while his perestroika ("restructuring") seeks to decentralize economic decision making to improve efficiency.

His democratization measures and formation of the elected Congress of People's Deputies undermines the one-party state.

Gorbachev declines to intervene militarily when various Eastern Bloc countries abandon Marxist-Leninist governance in 1989–90.

Internally, growing nationalist sentiment threatens to break up the Soviet Union, leading Marxist-Leninist hardliners to launch the unsuccessful August Coup against Gorbachev in 1991.

In the wake of this, the Soviet Union dissolves against Gorbachev's wishes and he resigns. 

leaving office, he launches his Gorbachev Foundation, becomes vocal critic of Russian Presidents Boris Yeltsin and Vladimir Putin, and campaigns for Russia's social-democratic movement.

Widely considered one of the most significant figures of the second half of the twentieth century, Gorbachev remains the subject of controversy.

The recipient of a wide range of awards—including the Nobel Peace Prize—he is widely praised for his pivotal role in ending the Cold War, curtailing human rights abuses in the Soviet Union, and tolerating both the fall of Marxist–Leninist administrations in eastern and central Europe and the reunification of Germany.

Conversely, in Russia he is often derided for not stopping the Soviet collapse, an event which brings a decline in Russia's global influence and precipitates an economic crisis.