 During Manuel II's reign, John VIII and the younger son Constantine appear to have got on well with each other, but the relations between Constantine and the younger brothers Demetrios and Thomas were not as friendly.Through most of John VIII's reign, Constantine and Thomas ruled as Despots of the Morea, with Demetrios governing a stretch of land in Thrace.Demetrios was unhappy with his subordinate position and assaulted Constantinople in 1442, with Ottoman help, in an attempt to seize the city and become emperor himself.