John V Palaiologos
Matthew Asanes Kantakouzenos was the son of Emperor John VI Kantakouzenos and Irene Asanina. In return for the support he gave to his father during his struggle with John V Palaiologos, he was given part of Thrace as an appanage in 1347, and was proclaimed joint emperor in 1353, when open civil war broke out again with John V.