The Bulgars, a Central Asian Turkic tribe, merged with the local Slavic inhabitants in the late 7th century to form the first Bulgarian state. In succeeding centuries, Bulgaria struggled with the Byzantine Empire to assert its place in the Balkans, but by the end of the 14th century the country was overrun by the Ottoman Turks. Northern Bulgaria attained autonomy in 1878 and all of Bulgaria became independent from the Ottoman Empire in 1908. Having fought on the losing side in both World Wars, Bulgaria fell within the Soviet sphere of influence and became a People's Republic in 1946. Communist domination ended in 1990, when Bulgaria held its first multiparty election since World War II and began the contentious process of moving toward political democracy and a market economy while combating inflation, unemployment, corruption, and crime. The country joined NATO in 2004 and the EU in 2007. Source: World Factbook.
When Soviet troops arrived in Bulgaria, they were welcomed by the populace as liberators from German occupation. On September 9, 1944, five days after the Soviet declaration of war, a Fatherland Front coalition deposed the temporary government in a bloodless coup. Headed by Kimon Georgiev of Zveno, the new administration included four communists, five members of Zveno, two social democrats, and four agrarians. Although in the minority, the communists had been the driving force in forming the coalition as an underground resistance organization in 1942. The presence of the Red Army, which remained in Bulgaria until 1947, strengthened immeasurably the communist position in dealing with the Allies and rival factions in the coalition. At this point, many noncommunist Bulgarians placed their hopes on renewed relations with the Soviet Union; in their view, both Germany and the Allies had been discredited by the events of the previous fifteen years. In 1945 the Allies themselves expected that a benign Soviet Union would continue the wartime alliance through the period of postwar East European realignment.
The armistice signed by Bulgaria with the Soviet Union in October 1944 surrendered all wartime territorial gains except Southern Dobruja; this meant that Macedonia returned to Yugoslavia and Thrace to Greece. The peace agreement also established a Soviet-dominated Allied Control Commission to run Bulgaria until conclusion of a peace treaty. Overall war damage to Bulgaria was moderate compared to that in other European countries, and the Soviet Union demanded no reparations. On the other hand, Bulgaria held the earliest and most widespread war crimes trial in postwar Europe; almost 3,000 were executed as war criminals. Bulgaria emerged from the war with no identifiable political structure; the party system had dissolved in 1934, replaced by the pragmatic balancing of political factions in Boris's royal dictatorship. This condition and the duration of the war in Europe eight months after Bulgaria's surrender gave the communists ample opportunity to exploit their favorable strategic position in Bulgarian politics. Source: Bulgaria: A Country Study.