Who was the President of the USSR?

Mikhail Gorbachev is a Russian politician, author of perestroika (recreating), glasnost (publicity), uskorenie (acceleration) which purpose was to abolish communism in the USSR and to finish a Cold War. He left his post 25 Dec 1991 what symbolised the end of the almost 70 years of this country's tradition. In Russia, Gorbachev is remembered to have been responsible for destroying an empire. He got the Nobel Prize in 1990. Nowadays he is still active in public life but not taking part in Russian politics.