On August 18, 1991, Soviet President Mikhail Gorbachev is placed under house arrest during a coup by high-ranking members of his own government, military and police forces.

Since becoming secretary of the Communist Party in 1985 and president of the Union of Soviet Socialist Republics (USSR) in 1988, Gorbachev had pursued comprehensive reforms of the Soviet system. Combining perestroika (“restructuring”) of the economy–including a greater emphasis on free-market policies–and glasnost (“openness”) in diplomacy, he greatly improved Soviet relations with Western democracies, particularly the United States. Meanwhile, though, within the USSR, Gorbachev faced powerful critics, including conservative, hard-line politicians and military officials who thought he was driving the Soviet Union toward its downfall and making it a second-rate power. On the other side were even more radical reformers–particularly Boris Yeltsin, president of the most powerful socialist republic, Russia–who complained that Gorbachev was just not working fast enough.

The August 1991 coup was carried out by the hard-line elements within Gorbachev’s own administration, as well as the heads of the Soviet army and the KGB, or secret police. Detained at his vacation villa in the Crimea, he was placed under house arrest and pressured to give his resignation, which he refused to do. Claiming Gorbachev was ill, the coup leaders, headed by former vice president Gennady Yanayev, declared a state of emergency and attempted to take control of the government.

Yeltsin and his backers from the Russian parliament then stepped in, calling on the Russian people to strike and protest the coup. When soldiers tried to arrest Yeltsin, they found the way to the parliamentary building blocked by armed and unarmed civilians. Yeltsin himself climbed aboard a tank and spoke through a megaphone, urging the troops not to turn against the people and condemning the coup as a “new reign of terror.” The soldiers backed off, some of them choosing to join the resistance. After thousands took the streets to demonstrate, the coup collapsed after only three days.

Gorbachev was released and flown to Moscow, but his regime had been dealt a deadly blow. Over the next few months, he dissolved the Communist Party, granted independence to the Baltic states, and proposed a looser, more economics-based federation among the remaining republics. In December 1991, Gorbachev resigned. Yeltsin capitalized on his defeat of the coup, emerging from the rubble of the former Soviet Union as the most powerful figure in Moscow and the leader of the newly formed Commonwealth of Independent States (CIS).