The town played a prominent role in the Byzantine civil wars of the mid-14th century. In 1344, during the war of 1341–1347, the well-fortified town was captured by John VI Kantakouzenos (r. 1341–1354), who appointed his son Matthew to rule over it and the surrounding province. Gratzianous remained the seat of Matthew and his family until 1355/56, when, after another civil war, he surrendered it and all his Thracian domains to John V Palaiologos (r. 1341–1391) in exchange for the Despotate of the Morea.