The August Coup (August 19th to 22nd 1991) was an attempt by hardliners in the Communist Party of the Soviet Union to oust revisionist Mikhail Gorbachev from office and roll-back his policies. The coup, which was planned as early as September 1990, consisted of top military and civilian officials, including Vice President Gennady Yanayev, who together formed the State Committee on the State of Emergency (GKChP). They opposed Gorbachev's reform programs, were angry at the loss of control over Eastern European states and fearful of the USSR's New Union Treaty which was on the verge of being signed. The treaty was to decentralize much of the central Soviet government's power and distribute it among its fifteen republics.
The GKChP hardliners dispatched KGB agents, who detained Gorbachev at his dacha in Crimea but failed to detain the recently elected president of a newly reconstituted Russia, Boris Yeltsin, who had been both an ally and critic of Gorbachev. The coup's failure was instrumental in the counterrevolution which overthrew the Soviet Union four months later in December 1991.