 He was 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 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.