Prague, 20 August 1998 (RFE/RL) -- The following is a chronology of the significant events leading up to the Warsaw Pact invasion of Czechoslovakia in the summer of 1968:
Jan. 5, 1968: Alexander Dubcek replaces Antonin Novotny as Party leader and declares his intention to press ahead with extensive reforms. Novotny was criticized by party liberals and intellectuals for his government's poor economic performance and his anti-Slovak prejudice. Dubcek is seen as the perfect compromise candidate, acceptable to both the orthodox party members and reform wing.
February: Communist Party leadership approves enlargement of the economic reform program started in 1967. Journalists, students, and writers call for the repeal of the 1966 Press censorship law.
March: Public rallies held in Prague and other cities and towns in support of reform policies voice growing criticism of Novotny's presidency.
March 22: Novotny resigns as president, after facing pressure by party liberals.
March 30: General Ludvik Svoboda is elected president of Czechoslovakia. Svoboda was a war hero who had also served in the Czechoslovak legion at the start of the Russian Civil War in 1918.
April 5: Action Program of the Communist Party is published, part of the effort to provide "socialism with a human face." It calls for the "democratization" of the political and economic system. The document refers to a "unique experiment in democratic communism." The Communist Party would now have to compete with other parties in elections. Document envisages a gradual reform of the political system over a 10-year period.
April 18: A new government is formed under Dubcek ally and reformer Oldrich Cernik. Liberalization process goes full swing. Press continues to become more outspoken in support of freedoms.
May 1: May Day celebrations show huge support for the new cause.
May 4-5: Czechoslovak leaders visit Moscow: Soviet leadership expresses dissatisfaction with developments in Czechoslovakia.
May 29: A number of high-ranking Soviet military officials visit Czechoslovakia to lay the groundwork for Soviet military exercises.
June 26: Censorship is officially abolished.
June 27: Two Thousand Words manifesto signed by reformers, including some Central Committee members, is published in Literarny Listy and other publications. It calls for "democratization," the re-establishment of the Social Democratic Party, and the setting up of citizens' committees. The manifesto is a more radical alternative to the Communist Party's April Action Program The political leadership (including Dubcek) rejects the manifesto.
July 4: Beginning of Soviet-led military exercizes in Sumava, aimed at strengthening the hand of anti-reformist forces in Czechoslovakia.
July 15: Representatives of the Communist parties of the Soviet Union, Hungary, Poland, East Germany and Bulgaria meet in Warsaw. They send a strongly worded diplomatic note warning the new Czechoslovak leaders that "the situation in Czechoslovakia jeopardizes the common vital interests of other socialist countries."
July 29-Aug. 1: Negotiations are held between the presidiums of the Czechoslovak and Soviet communist parties in Cierna-nad-Tisou. Dubcek argues that reforms did not endanger the role of the party but built public support. The Soviets do not accept these arguments and sharply criticize the Czechoslovak moves. Threats of invasion are made.
July 31: East Germany, Poland, Hungary and Soviet Union announce that they will hold military exercises near the Czechoslovak border.
Aug. 3: A Warsaw Pact meeting (without Romania) is held in Bratislava. The meeting brings about a seeming reconciliation between the Warsaw Pact leaders and the Czechoslovak leadership. Here for the first time, the so-called Brezhnev doctrine of limited sovereigny is announced. Soviet leader Leonid Brezhnev receives a handwritten letter from five members of the Czechoslovak Presidium who warn that the socialist order is under threat. They request military intervention.
Aug. 18: The Kremlin decides on the invasion of Czechoslovakia. The commander of Soviet Central Forces, General Aleksandr Mayorov, relates how Soviet Defense Minister Andrei Grechko stated to the assembled Soviet Politburo and military leaders: "the invasion will take place even if it leads to a third world war."
Aug. 20: Czechoslovakia is invaded by an estimated 500,000 troops from the armies of five Warsaw pact countries (Soviet Union, Poland, Hungary, Bulgaria, and East Germany) overnight into Aug. 21.
Aug. 21, Shortly after 0100: State Radio announces invasion by troops from five Warsaw Pact countries. It says the invasion took place without the knowledge of the Czechoslovak authorities. "The Presidium calls upon all citizens of the Republic to keep the peace and not resist the advancing armies , because the defense of our borders is now impossible." The army is given orders to remain in its barracks and not to offer resistance.
Aug. 21, 0300: Czechoslovak Premier Oldrich Cernik, Dubcek, Jozef Smrkovsky and Frantisek Kriegel -- the four leading reformers in Czechoslovak leadership -- are arrested in the Communist Party's Presidium building by Soviet airborne troops.
Occupation governments distribute leaflets saying the troops were sent in "to come to the aid of the working class and all the people of Czechoslovak to defend socialist gains."
Aug. 21, 0530: Tass says that Czechoslovak Party and government officials requested urgent assistance from the Soviet Union and other fraternal countries.
Aug. 21, 0600: Svoboda makes radio address calling for calm and for people to go to work as normal.
Aug. 21, 0800: Crowds and Soviet troops confront one another on Old Town Square and Wenceslas Square. Tanks appear at the Museum and start firing at nearby buildings and the National museum.
Dubcek and other party leaders are flown to Moscow and are compelled to participate in talks with Moscow leadership. They sign a document in which they renounce parts of the reform program and agree to the presence of Soviet troops in Czechoslovakia.
Invasion draws condemnation from Western powers as well as communist and socialist parties in the West. U.S. President Lyndon B. Johnson calls on Soviets to withdraw from Czechoslovakia.
Aug. 23: Svoboda flies to Moscow with large delegation of Czechoslovak Communist leaders to negotiate a solution.
Aug. 25: Czechoslovak leaders sign so-called Moscow protocol which renounces parts of the reform program and agrees to the presence of Soviet troops in Czechoslovakia.
Aug. 27: Svoboda returns to Prague with Dubcek, Cernik.
Aug. 31: 14th Party Congress declared invalid, as required by the Moscow protocol. Censorship is reintroduced in the country.
Oct. 28: Czechoslovakia becomes a federal republic, the only major objective of the reform process that came to fruition.
Jan 16, 1969: Czechoslovak student Jan Palach sets himself afire in protest.
April 17, 1969: Dubcek removed as party first secretary, after disturbances that follow Czechoslovak hockey team's victory over a Soviet team in Stockholm. Dubcek replaced by Gustav Husak with full support of the Soviet Union.