Battle of Bizye

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. 

The Bulgarian troops withdrew immediately, and the Byzantines captured the fortress of Diampolis (Yambol) and withdrew.