The original sources differ on their explanation of Mehmed's actual motivations for attacking Trebizond. William Miller quotes Kritoboulos as stating that Emperor David of Trebizond's "reluctance to pay tribute and the intermarriages with Hassan and the Georgian court provoked the Sultan to invade the Empire."[6] On the other hand, Halil İnalcık cites a passage from the 15th-century Ottoman historian Kemal Pasha-zade, who wrote:[7]