Battle of Bukelon

Despite temporarily improving relations with Byzantium and his marriage to Theodora Palaiologina, granddaughter of the granddaughter of the Byzantine emperor at the time, Andronikos II, and sister of the claimant to the Byzantine throne, Andronikos III, Tsar Michael III Shishman undertook new military action against Byzantium. His troops invaded Thrace, where they were about to encounter Andronikos III's Byzantine forces near the town of Bizye. He lost the battle there and withdrew. Two months later, however, he invaded Eastern Thrace again, and this time fighting took place at the fortress of Bukelon. 

Bulgaria won the engagement and captured the fortress of Bukelon, near the village of Matochina in the Svilengrad area.