During the First Balkan War, the Balkan League (Serbia, Greece, Bulgaria and Montenegro) fought against the Ottoman Empire and annexed most of its European territory, including Thrace. Western Thrace was occupied by Bulgarian troops who defeated the Ottoman army. On November 15, 1912 on the right bank of the river Maritza Macedonian-Adrianopolitan Volunteer Corps captured the Turkish corps of Yaver Paha, which defends the Eastern Rhodopes and Western Thrace from invading Bulgarians.