Russia today marked the 50th anniversary of Nikita Khrushchev's "secret speech," in which he denounced the crimes committed under dictator Josef Stalin and the cult of personality surrounding the deceased Soviet leader. Today was an occasion for Russians to reexamine the impact of this legendary speech on their country's history.

Khrushchev's speech at the 20th Congress of the Communist Party of the Soviet Union -- held 14-25 February 1956 -- entered history as the first step toward de-Stalinization.

In this speech, Khrushchev accused his predecessor, Josef Stalin, of creating a regime based on "suspicion, fear, and terror." Khrushchev added that he wanted to break the cult of Stalin, who had died three years before.

He condemned the mass repressions that took place between 1936 and 1938, lashed out at Stalin's foreign policy during World War II, and accused him of nationalism and anti-Semitism.

Khrushchev was the first official publicly to denounce Stalin's policies, and his sensational speech stunned the senior party officials gathered at the congress.

According to delegates who witnessed the speech, it provoked deep shock among the audience -- many delegates were reportedly crying, others were holding their heads in despair, and several even had heart attacks in the conference hall.

Khrushchev's denunciation of Stalinism became known as the "secret speech," since it was delivered behind closed doors and was not made public until 18 March 1956.

Roy Medvedev, a historian who in 1956 was a school director in a provincial Russian city, describes how he first heard the content of the speech.

"They gathered activists, all the party members, all the Komsomol members, the directors of kolkhozs [communal farms[ and sovkhozs [state farms]," Medvedev says. "The instructor of the district Communist Party arrived, took out a red book, and told us: 'I am going to read you the secret speech of Nikita Sergeevich Khrushchev at the 20th congress.' For four hours, we listed to this report. There were people present who had fought in World War II and worshipped Stalin. There were people like me, whose father was repressed and died in prison and who knew about torture and camps."

In the aftermath of the speech, tens of thousands of political prisoners were set free. Khrushchev's words also had huge repercussions in Eastern Europe, where it fuelled hopes of political change, particularly in Poland and Hungary.

Secrecy, however, shrouded the speech for many years -- the full text was not published in Russia until 1988, some 32 years later.

Medvedev says it took a long time for him to realize its full impact.

"The press was not reporting anything," Medvedev says. "There was no television back then, no information. Very serious processes were set in motion about which we knew nothing. Two days or so after the congress, Western Communist parties protested. They asked why this had to be done. A secret correspondence immediately started with the Chinese Communist Party, which resolutely condemned the 20th congress. It was an event of colossal historical significance."

While most communists still view it as an act of treason and say it has done more harm than good, many observers hail it as the beginning of the end of the repressive Stalinist era.

Former Soviet President Mikhail Gorbachev said yesterday that Khrushchev's speech had much wider implications than just demolishing the cult of Stalin.

He said it laid the foundation for perestroika by addressing, in his words, "not only the cult of personality, but also democratic problems and ways to manage the country."

Historians have often described Khrushchev as a liberal reformer. They stress, however, that this "liberalism" soon showed its limits. Just nine months later, in November 1956, Soviet tanks were crushing an anti-Soviet uprising in Hungary, killing thousands of protesters.