Bulgarian rule of Macedonia, Morava Valley and Western Thrace (1941–1944)
During Bulgaria's participation in World War II as a member of the Tripartite Pact (1941–1944), the Kingdom of Bulgaria unilaterally annexed several Yugoslav and Greek territories, including most of Macedonia, the Morava Valley, and Western Thrace. As a result of these annexations, Bulgaria acquired a total of 39,756.6 km2, distributed as follows: the Western Outlands (2,968 km2), Macedonia (23,807 km2), Western Thrace (12,363 km2), the island of Thasos (443 km2), and the island of Samothrace (184 km2).