Like many European air arms, the history of the Bulgarian Air Force between 1939 and 1945 was eventful and rather dramatic. A small country, located in the heart of the Balkan Peninsula, the Kingdom of Bulgaria entered into the fourth decade of the century as a still-neutral, but in fact strongly pro-German state. So it was not a surprise when it eventually joined the Axis on 1 March 1941, declaring war on both Britain and the US six months later. In the course of the war the moderate and poorly equipped air arm of late 1930s steadily matured during the wartime years into a small but capable force, able to mount fierce resistance to the Allied bomber raids against the country’s capital Sofia in late 1943 and early 1944. Only a few hours following the 9 September 1944 pro-Allied coup in Sofia, the Bulgarian air arm was immediately rushed into operation against the armed forces of the yesterday's partner - Nazi Germany.After the end of the war, Bulgaria fell in total dependency on the Soviet Union as a direct result from the 1944 Yalta agreement of 'spheres of influence' division of Europe. The Bulgarian air force was radically reformed in the Soviet style and rapidly re-equipped with huge numbers of front-line aircraft, supplied by the new 'brother in arms’. This study features a large number of rare and previously unseen photographs accompanied by specially commissioned color artwork showing camouflage and markings.