This was Konstantinos XIV of the Empire. His father had lost control of the Empire to another branch of the Doukas family, leaving Konstantinos merely the Duke of Thrace. His father had died in 1267, when he was four.
Despite these disadvantages, Konstantinos was able to reclaim the Empire before his 17th birthday, using the still large Scholai Palatinae to make strategic strikes on the false Emperor’s holdings.
While the false Emperor had been in charge, the Empire had begun to fall apart. Egypt and Jerusalem were lost, and the Emperor had little real authority.
Prodded by his wife, Konstaninos spent his life reclaiming nearly all the lands that had been lost, as well as much of the Aquitainian and Iberian coasts.
In 1328, at the age of 66, Konstantinos the XIV died, and was succeeded by his son, Konstantinos XV.