Mikhail Gorbachev, the last leader of the former Soviet Union, died Tuesday night at the age of 91, according to Russian state news agencies.
Gorbachev, who was credited with introducing key reforms to the USSR and helping to end the Cold War, had been in failing health for some time.
With his outgoing, charismatic nature, Gorbachev broke the mold for Soviet leaders who until then had mostly been remote, icy figures. Almost from the start of his leadership, he strove for significant reforms so the system would work more efficiently and more democratically. Two key phrases of the Gorbachev era were "glasnost" (openness) and "perestroika" (restructuring).