RSDr. Vasiľ Biľak (born 11 August 1917 in Krajná Bystrá) was a former Slovak Communist leader of Rusyn origin.

Vasiľ Biľak was originally a tailor. In the years 1955 – 1968 and 1969 – 1971 he was a member of the Central Committee of the Communist Party of Slovakia (ÚV KSS); in 1962 – 1968 he was the secretary and from January until August 1968 General secretary of ÚV KSS; from April 1968 until December 1988 a member of the Presidium of the Central Committee of the Communist Party of Czechoslovakia (ÚV KSČ). From November 1968 until December 1988 he was a secretary of ÚV KSČ with significant influence on the foreign policy and the ideology of the party. In 1960 – 1989 he was a member of National Assembly, later Federal Assembly.

In 1968 he belonged to the exponents of the hardline wing in the KSČ; he supported the Soviet invasion and participated on the so called "normalization process" after the political liberalization called the Prague Spring.

He was one of the politicians who signed the invitation letter for the armies of Warsaw Pact countries. In December 1989, he was suspended from the KSČ. The Slovak Justice Minister Jan Carnogursky said in 2001 he would not ask the Slovak President Rudolf Schuster to grant an amnesty to Vasil Bilak, the Czechoslovak Communist Party ideologist charged with treason in connection with the "invitation" sent to Warsaw Pact countries to extend "brotherly help" to Czechoslovakia in 1968. In 2011, the trial process with Bilak ended unsuccessfully, when the attorney stopped it for lack of witnesses.

Drahomir Kolder (29 December 1925 in Ostrava - 20 August 1972 in Prague) was a Czech Communist politician, official of the Communist Party, a member of the Bureau and secretary of the CPC Central Committee, Member of the National Assembly and the Federal Assembly of Czechoslovakia, Minister in the government of the Czech Socialist Republic.

He was connected with the events of the Prague Spring in1968 under the conservative wing, belonging to a narrow group of people that assembled the invitation letter, which preceded the invasion by the Warsaw Pact into Czechoslovakia .

In addition to his party functions, he served as chairman of the Central Commission's control, which was in the early 70s converted to Committee's control, which he headed since 1971 holding the office of Minister.

Oldrich Svestka ( 24 March 1922 in Pozorce near Teplice - 8 June 1983 in Prague) was a Czech Communist official, politician and journalist, member of the Central Committee of the Communist Party, Member of the Federal Assembly. He became notorious for collaborating during the events of the Czechoslovak Prague Spring in the summer of 1968 and in the subsequent normalization in the seventies.

From 1945 until 1958 he was editor of the party newspaper of the Central Communist Party Red right, since 1958 until his death,  its editor, with the only exception of the years 1968 to 1971, when he was editor of the party magazine Tribuna.

From 1971 until his death in 1983 he served as a member of the House of the People of the Federal Assembly of Czechoslovakia.

From 1962 until 1963 he was a member of the Central Committee of the CPC. He was one of the authors of the letter of invitation issued in1968, which was obviously an act raising the suspicion of treason. For this act, he was never prosecuted or punished.