The siege of Trebizond was the successful siege of the city of Trebizond, capital of the Empire of Trebizond, by the Ottomans under Sultan Mehmed II, which ended on 15 August 1461.[1] The siege was the culmination of a lengthy campaign on the Ottoman side, which involved co-ordinated but independent manoeuvres by a large army and navy. The Trapezuntine defenders had relied on a network of alliances that would provide them with support and manpower when the Ottomans began their siege, but failed at the moment Emperor David Megas Komnenos most needed it.