<P> On 23 August 1944, Romania left the Axis Powers and declared war on Germany, and allowed Soviet forces to cross its territory to reach Bulgaria . On 5 September 1944 the Soviet Union declared war on Bulgaria and invaded . Within three days, the Soviets occupied the northeastern part of Bulgaria along with the key port cities of Varna and Burgas . Meanwhile, on 5 of September, Bulgaria declared war on Nazi Germany . The Bulgarian Army was ordered to offer no resistance . </P> <P> On 9 September 1944 in a coup the government of Prime Minister Konstantin Muraviev was overthrown and replaced with a government of the Fatherland Front led by Kimon Georgiev . On 16 September 1944 the Soviet Red Army entered Sofia . The Bulgarian Army marked several victories against the 7th SS Volunteer Mountain Division Prinz Eugen (at Nish), the 22nd Infantry Division (at Strumica) and other German forces during the operations in Kosovo and at Stratsin . </P> <P> During this period the country was known as the "People's Republic of Bulgaria" (PRB) and was ruled by the Bulgarian Communist Party (BCP). The BCP transformed itself in 1990, changing its name to "Bulgarian Socialist Party". </P> <P> Although communist leader Dimitrov had been in exile, mostly in the Soviet Union, since 1923, he was not a Soviet puppet . He had shown great courage in Nazi Germany during the Reichstag fire trial of 1933 and had later headed the Comintern during the period of the Popular Front . He was also close to the Yugoslav Communist leader Tito and believed that Yugoslavia and Bulgaria, as closely related South Slav peoples, should form a federation . </P>

What type of government did bulgaria have from 1944 to 1990