Mikhail Gorbachev was the famous Russian leader who introduced perestroika and glasnost during the 1980s. Perestroika aimed at restructuring the Soviet political and economic systems, while glasnost promoted greater openness and transparency in government. Gorbachev's reforms were initially intended to revitalize the failing Soviet economy and liberalize society, but they inadvertently contributed to the dissolution of the Soviet Union in 1991. His policies sparked significant changes within Eastern Europe, leading to the end of communist regimes in several countries and altering the global geopolitical landscape.