Siege of Sinope

The Siege of Sinope in 1214 was a successful siege and capture of Sinope by the Seljuq Turks under their Sultan, Kaykaus I (r. 1211–1220).

Sinope was an important port city on the Black Sea coast of modern Turkey, at the time held by the Empire of Trebizond, one of the Byzantine Greek successor states formed after the Fourth Crusade. The siege is described in some detail by the near-contemporary Seljuq chronicler Ibn Bibi. The Trapezuntian emperor Alexios I (r. 1204–1222) led an army to raise it, but was defeated and captured, and the city surrendered on 1 November. Beginning with Fallmerayer, earlier scholars used to place the death of David Komnenos, Alexios' younger brother and co-founder of the Trapezuntian empire, during the siege of Sinope. Modern research, however, has shown that he died in exile as a monk in Mount Athos in 1212/1213.

The Seljuq capture of Sinope had important consequences: apart from a short period of Trapezuntian recovery in 1254–1265, the city henceforth remained in Turkish hands, cutting the small Trapezuntian state off from overland contact with the metropolitan Byzantine lands of the Empire of Nicaea in western Asia Minor. At the same time, the capture of its ruler forced the Trapezuntians to accept tributary status to the Seljuqs, which lasted until the failure of a Sejuq assault on Trebizond itself in 1222/1223. According to the Byzantinist Warren Treadgold, the loss of Sinope on the one hand "shielded Trebizond from further attacks from Nicaea", but also meant that "henceforth Alexios' claim to be Byzantine emperor rang hollow, and the Empire of Trebizond ceased to be of more than local importance."