He is one of the great figures of 20th-century European history: Václav Havel. Alongside Mikhail Gorbachev, Lech Wałęsa, and Karol Wojtyła, also known as Pope John Paul II, Havel profoundly changed the face of Eastern Europe. The world-renowned playwright and essayist was one of the leading voices of the critics of the communist regime in Czechoslovakia. As early as 1967, before the Prague Spring was crushed by the tanks of the Warsaw Pact, he protested against arbitrary power and censorship. In response, the writer was subjected to a publication ban. Havel was one of the initiators of Charter 77 and was the most prominent spokesperson for this civil rights movement. He was sentenced to prison terms and house arrest several times. At the end of 1989 - after the successful Velvet Revolution - Havel became the first freely elected president at Prague Castle.