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. == Battle ==