Byzantine civil war of 1341–1347 Part of the Byzantine civil wars, the Byzantine–Serbian wars and the Byzantine–Turkish wars Date September 1341 – 8 February 1347 Location Thessaly, Macedonia, Thrace, and Constantinople Result John VI Kantakouzenos defeats regents, and is recognized as senior emperor Territorial changes Serbs gain Macedonia (except Thessalonica) and Albania, and soon after Epirus and Thessaly, establishing the Serbian Empire; Bulgarians gain parts of northern Thrace Belligerents John V Palaiologos Regents: Anna of Savoy John XIV Kalekas Alexios Apokaukos Allies: Zealots of Thessalonica Serbia (1343–1347) Bulgaria Principality of Karvuna John VI Kantakouzenos Allies: Serbia (1342–1343) Beylik of Aydin (1342/3–1345) Ottoman beylik (1345–1347) Beylik of Saruhan Commanders and leaders Alexios Apokaukos Stefan IV Dušan Gregory Preljub Ivan Alexander Momchil (1344–1345) John VI Kantakouzenos Manuel Kantakouzenos John Angelos Stefan IV Dušan Hrelja Umur Bey Orhan