Hungary's transition from communism to democracy and capitalism (''rendszerváltás'', "regime change") was peaceful and prompted by economic stagnation, domestic political pressure, and changing relations with other Warsaw Pact countries. Although the MSzMP began Round Table Talks with various opposition groups in March 1989, the reburial of Imre Nagy as a revolutionary martyr that June is widely considered the symbolic end of communism in Hungary. Over 100,000 people attended the Budapest ceremony without any significant government interference, and many speakers openly called for Soviet troops to leave the country. Free elections were held in May 1990, and the Hungarian Democratic Forum, a major conservative opposition group, was elected to the head of a coalition government. József Antall became the first democratically elected Prime Minister since World War II.