(born 1931), Soviet statesman, general secretary of the Communist Party of the Soviet Union 1985–91 and president 1988–91; full name Mikhail Sergeevich Gorbachev. Domestically, he introduced major reforms (glasnost and perestroika), both in the economy and in freedom of information, and his foreign policy helped bring about an end to the Cold War. Opposition to his policies led to an attempted coup in 1991. His subsequent resignation following the establishment of the Commonwealth of Independent States effectively dissolved the Soviet Union. Nobel Peace Prize (1990).