The Byzantine civil war of 1352–1357 marks the continuation and conclusion of a previous conflict that lasted from 1341 to 1347. It involved John V Palaiologos against the two Kantakouzenoi, John VI Kantakouzenos and his eldest son Matthew Kantakouzenos. John V emerged victorious as the sole emperor of the Byzantine Empire, but the resumption of civil war completed the destruction of the previous conflict, leaving the Byzantine state in ruins.