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.