King Boris III

With the start of World War 2, Bulgaria was in a sticky position. It had just signed a treaty of "inviolable peace and friendship" with Serbia in 1937. Yet Germany by then had strong economic ties in the area, and with promises from the Reich of gaining back the ever-desirable Macedonian lands, Bulgaria reluctantly sided with the Axis powers in 1941. To avoid a revolt by the people, King Boris III refused to sign a declaration of war on the Soviets, and the Bulgarians avoided conflict with their traditional Slav allies for the duration of the war. Although he managed to resist Nazi pressure on that issue, Boris did die mysteriously after visiting Berlin in August 1943 (1991 scientific tests are said to prove that it was not poison which killed the king). He left behind a son, Simeon II, aged six, and a Council of Regency to rule in his stead.

Heavy Allied bombing raids destroyed much of Sofia in 1943-44, which served to increase the general anti-war and especially anti-Nazi sentiment. After declaring itself neutral and disarming locally stationed German soldiers, Bulgarians allowed the Red Army to pass its northern borders unopposed on September 8, 1944. The next day, a coalition of communist groups, which had been operating under the name of the Fatherland Front, took Sofia and then the rest of Bulgaria, and September 9 was deemed Liberation Day.