Battle of Peritheorion
The Battle of Peritheorion on 7 July 1345 was between the forces of Momchil, the quasi-independent ruler of Rhodope, and an allied Byzantine-Turkish force headed by John VI Kantakouzenos and Umur Bey of Aydin. The two armies met in front of the walls of the city of Peritheorion, and the battle resulted in a crushing victory for the allied army, with Momchil himself falling in the field.
Origins of the conflict
From 1341, a civil war had been going on in the Byzantine Empire between the regency for the infant John V Palaiologos and the former regent John VI Kantakouzenos. In this conflict, both sides called upon aid from neighbouring states. Kantakouzenos initially relied upon aid by Stefan Dushan of Serbia, but in 1343, the arrival of his old friend and ally, Umur Bey, greatly strengthened his position.In the same year, Momchil, a Bulgarian brigand active in the northern Rhodope mountains, pledged allegiance to Kantakouzenos. He was rewarded with the title of sebastokrator and given the governance of the region of Merope, stretching from east of the Nestos river to the vicinity of Komotini. In the next year however, Umur Bey was forced to withdraw with his forces to Anatolia, and Momchil defected to the regency's side, for which he was rewarded with the title of despotes. He began raiding the lands still loyal to Kantakouzenos and harassing the small Turkish forces left to Kantakouzenos, achieving a small victory when he burned a number of their ships at Porto Lago. By the time Umur returned in force in spring 1345, Momchil, taking advantage of his position in the no man's land between the warring Serbian, Bulgarian and Byzantine states, had established himself as a virtually independent prince in the area of the Rhodope.