Events in the year 1989 in Bulgaria. Incumbents General Secretaries of the Bulgarian Communist Party: Todor Zhivkov (from 1954 until November 10) Petar Mladenov (from November 10 until 1990) Chairmen of the Council of Ministers: Georgi Atanasov Events Long time ruler Zhivkov is ousted and a multiparty system is introduced. The opposition Union of Democratic Forces (UDF) party is formed. References 1980s in Bulgaria Years of the 20th century in Bulgaria Bulgaria Bulgaria