After two years of victorious campaigns against the Turks the indiscipline and the character of a foreign army in the heart of the Empire were seen as a growing danger, and on April 30 1305 the emperor's son (Michael IX Palaiologos) ordered mercenary Alans to murder Roger de Flor and exterminate the Company in Adrianople while they attended a banquet organised by the Emperor. About 100 cavalry men and 1,000 infantrymen perished.

After the murder of de Flor the local Byzantine population rose up against the Catalans in Constantinople and killed many of them, including at the main barracks. Prince Michael ensured that as many as possible were killed before news reached the main force in Gallipoli. Some however escaped and carried the news of the massacre to Gallipoli after which the Catalans went on a killing spree of their own, killing all the local Byzantines.