Attempted coup (August 18 - 22, 1991) against Soviet President Mikhail Gorbachev.
On the eve of the signing ceremony for a new union treaty for the Union of Soviet Socialist Republics, members of the Politburo and the heads of the Soviet military and security services detained Gorbachev at his villa in the Crimea. Claiming that Gorbachev had been removed from his position as president due to illness, the leaders of the coup formed an eight-man Committee of the State of Emergency (GKCP) and attempted to assume control of the government.
Russian parliamentarians, under the leadership of Boris Yeltsin, led popular resistance to the Committee's leadership. Soldiers and tanks sent to arrest Yeltsin found the Russian Parliament building surrounded by both armed and unarmed civilians. The soldiers then turned around, either returning to their barracks or joining the resistance.
Many junior officers and officials in the Moscow ministries, as well as the leadership of the Soviet Union's constituent republics, denounced the new leadership. The coup collapsed as the Committee found itself lacking either the will or the loyalty of the military necessary to put down the burgeoning resistance movement.
Gorbachev was released from detention and flown to Moscow. Real power in Russia, however, had devolved to Yeltsin, who used the coup's failure to eliminate the political power of the Communist party of the Soviet Union.
The August Coup resulted in a minimal loss of life (3 deaths in Moscow and 3 in the Baltic States), the end of the CPSU's dominance, and hastened the disintegration of the Soviet Union.
The Failed Coup of August 1991