The Byzantine civil war of 1341–1347, sometimes referred to as the Second Palaiologan Civil War, was a conflict that broke out in the Byzantine Empire after the death of Andronikos III Palaiologos over the guardianship of his nine-year-old son and heir, John V Palaiologos. It pitted on the one hand Andronikos III's chief minister, John VI Kantakouzenos, and on the other a regency headed by the Empress-Dowager Anna of Savoy, the Patriarch of Constantinople John XIV Kalekas, and the megas doux Alexios Apokaukos. The war polarized Byzantine society along class lines, with the aristocracy backing Kantakouzenos and the lower and middle classes supporting the regency. To a lesser extent, the conflict acquired religious overtones; Byzantium was embroiled in the Hesychast controversy, and adherence to the mystical doctrine of Hesychasm was often equated with support for Kantakouzenos.

Andronikos III Palaiologos, commonly Latinized as Andronicus III Palaeologus, was the Byzantine emperor from 1328 to 1341. He was the son of Michael IX Palaiologos and Rita of Armenia. He was proclaimed co-emperor in his youth, before 1313, and in April 1321 he rebelled against his grandfather, Andronikos II Palaiologos. He was formally crowned co-emperor in February 1325, before ousting his grandfather outright and becoming sole emperor on 24 May 1328.