Mikhail Gorbachev was elected General Secretary by the Politburo on March 11, 1985, three hours after predecessor Konstantin Chernenko's death at age 73.
On July 1, 1985, Gorbachev promoted Eduard Shevardnadze, First Secretary of the Georgian Communist Party, to full member of the Politburo, and the following day appointed him minister of foreign affairs, replacing longtime Foreign Minister Andrei Gromyko.
On December 23, 1985, Gorbachev appointed Yeltsin First Secretary of the Moscow Communist Party replacing Viktor Grishin.
First anti-Soviet protests in Lithuania took place on August 23, 1987.
On August 23, 1987, the 48th anniversary of the secret protocols of the 1939 Molotov Pact between Adolf Hitler and Joseph Stalin that ultimately turned the then-independent Baltic states over to the Soviet Union, thousands of demonstrators marked the occasion in the three Baltic capitals to sing independence songs and attend speeches commemorating Stalin's victims. The gatherings were sharply denounced in the official press and closely watched by the police but were not interrupted.
On October 17, 1987, about 3,000 Armenians demonstrated in Yerevan complaining about the condition of Lake Sevan, the Nairit chemicals plant, and the Metsamor Nuclear Power Plant, and air pollution in Yerevan.
On October 21, a demonstration dedicated to those who gave their lives in the 1918–1920 Estonian War of Independence took place in Võru, which culminated in a conflict with the militia. For the first time in years, the blue, black, and white national tricolor was publicly displayed.
On November 18, 1987, hundreds of police and civilian militiamen cordoned off the central square to prevent any demonstration at Freedom Monument, but thousands lined the streets of Riga in silent protest regardless.
On February 20, 1988, after a week of growing demonstrations in Stepanakert, capital of the Nagorno-Karabakh Autonomous Oblast (the Armenian majority area within the Azerbaijan Soviet Socialist Republic), the Regional Soviet voted to secede and join with the Soviet Socialist Republic of Armenia.
The Estonian Popular Front was founded in April 1988.
On April 26, 1988, about 500 people participated in a march organized by the Ukrainian Cultural Club on Kiev's Khreschatyk Street to mark the second anniversary of the Chernobyl nuclear disaster, carrying placards with slogans like "Openness and Democracy to the End".
The Popular Front of Lithuania, called Sąjūdis ("Movement"), was founded in May 1988.
The Latvian Popular Front was founded in June 1988.
In Tbilisi, capital of Soviet Georgia, many demonstrators camped out in front of the republic's legislature in November 1988 calling for Georgia's independence and in support of Estonia's declaration of sovereignty.
On November 16, 1988, the Supreme Soviet of the Estonian SSR adopted a declaration of national sovereignty under which Estonian laws would take precedence over those of the Soviet Union.
In Ukraine, Lviv and Kiev celebrated Ukrainian Independence Day on January 22, 1989. Thousands gathered in Lviv for an unauthorized moleben (religious service) in front of St. George's Cathedral. In Kiev, 60 activists met in a Kiev apartment to commemorate the proclamation of the Ukrainian People's Republic in 1918.
On March 4, 1989, the Memorial Society, committed to honoring the victims of Stalinism and cleansing society of Soviet practices, was founded in Kiev. A public rally was held the next day.
On April 7, 1989, Soviet troops and armored personnel carriers were sent to Tbilisi after more than 100,000 people protested in front of Communist Party headquarters with banners calling for Georgia to secede from the Soviet Union and for Abkhazia to be fully integrated into Georgia.
On April 9, 1989, troops attacked the demonstrators; some 20 people were killed and more than 200 wounded. This event radicalized Georgian politics, prompting many to conclude that independence was preferable to continued Soviet rule.
On May 30, 1989, Gorbachev proposed that nationwide local elections, scheduled for November 1989, be postponed until early 1990 because there were still no laws governing the conduct of such elections. This was seen by some as a concession to local Party officials, who feared they would be swept from power in a wave of anti-establishment sentiment.
In Kazakhstan on June 19, 1989, young men carrying guns, firebombs, iron bars and stones rioted in Zhanaozen, causing a number of deaths. The youths tried to seize a police station and a water-supply station.
On June 23, 1989, Gorbachev removed Rafiq Nishonov as First Secretary of the Communist Party of the Uzbek SSR and replaced him with Karimov, who went on to lead Uzbekistan as a Soviet Republic and subsequently as an independent state.
On August 19, 600,000 protesters jammed Baku's Lenin Square (now Azadliq Square) to demand the release of political prisoners.
On August 19, 1989, the Russian Orthodox Parish of Saints Peter and Paul announced it would be switching to the Ukrainian Autocephalous Orthodox Church.
The Baltic Way or Baltic Chain was a peaceful political demonstration on August 23, 1989.
An estimated 2 million people joined hands to form a human chain extending 600 kilometres (370 mi) across Estonia, Latvia and Lithuania.
On September 30, 1989, thousands of Byelorussians, denouncing local leaders, marched through Minsk to demand additional cleanup of the 1986 Chernobyl disaster site in Ukraine.
On October 26, twenty factories in Lviv held strikes and meetings to protest the police brutality of October 1 and the authorities' unwillingness to prosecute those responsible.
On October 28, 1989, the Ukrainian Supreme Soviet decreed that effective January 1, 1990, Ukrainian would be the official language of Ukraine, while Russian would be used for communication between ethnic groups.
On December 7, 1989, the Communist Party of Lithuania under the leadership of Algirdas Brazauskas, split from the Communist Party of the Soviet Union and abandoned its claim to have a constitutional "leading role" in politics.
On December 10, 1989, the first officially sanctioned observance of International Human Rights Day was held in Lviv.
On December 26, the Supreme Soviet of Ukrainian SSR adopted a law designating Christmas, Easter, and the Feast of the Holy Trinity official holidays.
On February 7, 1990, the Central Committee of the CPSU accepted Gorbachev's recommendation that the party give up its monopoly on political power.
On March 4, 1990, the Russian Soviet Federative Socialist Republic held elections for the Congress of People's Deputies of Russia. Boris Yeltsin was elected, representing Sverdlovsk, garnering 72 percent of the vote.
On March 25, 1990, the Estonian Communist Party voted to split from the CPSU after a six-month transition.
On March 30, 1990, the Estonian Supreme Council declared the Soviet occupation of Estonia since World War II to be illegal and began reestablishing Estonia as an independent state.
On April 3, 1990, Edgar Savisaar of the Popular Front of Estonia was elected chairman of the Council of Ministers (the equivalent of being Prime Minister).
Latvia declared the restoration of independence on May 4, 1990, with the declaration stipulating a transitional period to complete independence.
On May 7, 1990, Ivars Godmanis of the Latvian Popular Front was elected chairman of the Council of Ministers (the equivalent of being Latvia's Prime Minister).
On May 29, 1990, Yeltsin was elected chair of the Presidium of the Supreme Soviet of the RSFSR,
Yeltsin was supported by democratic and conservative members of the Supreme Soviet, who sought power in the developing political situation. A new power struggle emerged between the RSFSR and the Soviet Union. On June 12, 1990, the Congress of People's Deputies of the RSFSR adopted a declaration of sovereignty.
On July 12, 1990, Yeltsin resigned from the Communist Party in a dramatic speech at the 28th Congress.
On January 13, 1991, Soviet troops, along with the KGB Spetsnaz Alpha Group, stormed the Vilnius TV Tower in Lithuania to suppress the independence movement.
On January 14, 1991, Nikolai Ryzhkov resigned from his post as Chairman of the Council of Ministers, or premier of the Soviet Union, and was succeeded by Valentin Pavlov in the newly established post of Prime Minister of the Soviet Union.
On March 17, 1991, in a Union-wide referendum 76.4 percent of voters endorsed retention of a reformed Soviet Union.
On June 12, 1991, Boris Yeltsin won 57 percent of the popular vote in the democratic elections, defeating Gorbachev's preferred candidate, Nikolai Ryzhkov, who won 16 percent of the vote. Following Yeltsin's election as president, Russia declared itself independent.
On August 19, 1991, Gorbachev's vice president, Gennady Yanayev, Prime Minister Valentin Pavlov, Defense Minister Dmitry Yazov, KGB chief Vladimir Kryuchkov and other senior officials acted to prevent the union treaty from being signed by forming the "General Committee on the State Emergency", which put Gorbachev – on holiday in Foros, Crimea – under house arrest and cut off his communications.
Faced with growing separatism, Gorbachev sought to restructure the Soviet Union into a less centralized state. On August 20, 1991, the Russian SFSR was scheduled to sign a New Union Treaty that would have converted the Soviet Union into a federation of independent republics with a common president, foreign policy and military. It was strongly supported by the Central Asian republics, which needed the economic advantages of a common market to prosper.
Estonia had officially restored its independence during the coup in the dark hours of August 20, 1991, at 11:03 pm Tallinn time, many Estonian volunteers surrounded the Tallinn TV Tower in an attempt to prepare to cut off the communication channels after the Soviet troops seized it and refused to be intimidated by the Soviet troops. When Edgar Savisaar confronted the Soviet troops for ten minutes, they finally retreated from the TV tower after a failed resistance against the Estonians.
On August 21, 1991, the coup collapsed. The organizers were detained and Gorbachev was reinstated as president, albeit with his power much depleted.
On August 24, 1991, Gorbachev dissolved the Central Committee of the CPSU, resigned as the party's general secretary, and dissolved all party units in the government.
On September 17, 1991, General Assembly resolution numbers 46/4, 46/5, and 46/6 admitted Estonia, Latvia, and Lithuania to the United Nations, conforming to Security Council resolution numbers 709, 710, and 711 passed on September 12 without a vote.
By 7 November 1991, most newspapers referred to the country as the 'former Soviet Union'.
The final round of the Soviet Union's collapse began with a Ukrainian popular referendum on December 1, 1991, in which 90 percent of voters opted for independence.
On December 8, the leaders of Russia, Ukraine, and Belarus secretly met in Belavezhskaya Pushcha, in western Belarus, and signed the Belavezha Accords, which proclaimed the Soviet Union had ceased to exist and announced formation of the Commonwealth of Independent States (CIS) as a looser association to take its place.
On December 12, the Supreme Soviet of the Russian SFSR formally ratified the Belavezha Accords and renounced the 1922 Union Treaty.
On December 17, 1991, along with 28 European countries, the European Economic Community, and four non-European countries, the three Baltic Republics and nine of the twelve remaining Soviet republics signed the European Energy Charter in the Hague as sovereign states.
Doubts remained over whether the Belavezha Accords had legally dissolved the Soviet Union, since they were signed by only three republics. However, on December 21, 1991, representatives of 11 of the 12 remaining republics – all except Georgia – signed the Alma-Ata Protocol, which confirmed the dissolution of the Union and formally established the CIS. They also "accepted" Gorbachev's resignation. While Gorbachev hadn't made any formal plans to leave the scene yet, he did tell CBS News that he would resign as soon as he saw that the CIS was indeed a reality.
In a nationally televised speech early in the morning of December 25, 1991, Gorbachev resigned as president of the USSR.
The President of the United States George H.W. Bush held a brief televised speech officially recognizing the independence of the 11 remaining republics.
On the night of December 25, at 7:32 p.m. Moscow time, after Gorbachev left the Kremlin, the Soviet flag was lowered for the last time, and the Russian tricolor was raised in its place at 11:40 pm, symbolically marking the end of the Soviet Union.
On December 26, the Council of the Republics, the upper chamber of the Union's Supreme Soviet, voted both itself and the Soviet Union out of existence.