Bulgaria during World War II

The history of Bulgaria during World War II encompasses an initial period of neutrality until 1 March 1941, a period of alliance with the Axis powers until 8 September 1944, and a period of alignment with the Allies in the final year of the war. With German consent, Bulgarian military forces occupied parts of the Kingdoms of Greece and Yugoslavia which Bulgarian irredentism claimed on the basis of the 1878 Treaty of San Stefano.

Source: Wikipedia — Bulgaria during World War II (CC BY-SA 4.0)