Republic in southeastern Europe in the eastern part of the Balkan Peninsula, bordered by Romania to the north, the Black Sea to the east, Turkey to the southeast, Greece to the south, and Macedonia and Yugoslavia to the west. Its capital and largest city is Sofia.
Note: Former Eastern Bloc country. Soviet troops entered Bulgaria in 1944, and a communist government was established soon thereafter. Bulgaria's communist rulers followed the Soviet lead for almost fifty years, until the collapse of the Soviet Union. In January 1991, a multiparty government began to institute democratic and economic reforms.