Manuel III Megas Komnenos (; 16 December 13645 March 1417) was Emperor of Trebizond from 20 March, 1390 to his death in 1417. The major event of Manuel's reign was the arrival of the Central Asian conqueror Tamerlane to Anatolia. This led to the virtual destruction of the Ottoman Empire, which had threatened the existence of Manuel's domain, in the Battle of Ankara. Although the Ottomans reconstituted their state after 10 years of civil war, this defeat extended the life and security of the Empire of Trebizond for several more decades. Life Manuel was the son of Emperor Alexios III of Trebizond by Theodora Kantakouzene. He was made heir apparent in 1377, after the death of his elder brother Basil. Manuel's domain had come under the growing threat of the ruler of the Ottoman Empire, Sultan Bayezid I, who in 1398 had led his army along the Black Sea coast as far as the border of the Empire of Trebizond. Tamerlane, who had campaigned in eastern Anatolia in 1394, returned and captured Sivas (27 August 1400), slaughtering all of its defenders. Tamerlane demanded that Manuel and his army join him in the coming war with the Ottoman Turks, but somehow the Emperor avoided this demand, although he did contribute twenty galleys to Tamerlane's general effort. Bayezid and Tamerlane finally met in the Battle of Ankara, where Tamerlane crushed the Ottoman forces and made the Sultan his prisoner. For the next eight months Tamerlane moved about Anatolia, restoring the old Turkish beyliks and plundering Ottoman territories, thus dismantling the Ottoman Empire. It would not be until 1413, when Mehmet I defeated his last surviving brother, that the Ottoman Empire would once more be a threat to any of its neighbors. When Tamerlane left Asia Minor in 1403, part of his army detached from the whole to visit the city of Kerasous and it was presumably by their ravages that the rule of Melissenos at Oinaion was destroyed. Only the mountains around Kerasous prevented them from venturing any further, much to the relief of the people of Trebizond. Tamerlane also put his nephew Mirza Halil in charge of the affairs of Armenia, Trebizond, and Georgia, but with his father's death in 1405 Halil rushed off to assume the throne at Samarkand. The ambassador to Tamerlane Ruy Gonzáles de Clavijo was received by Manuel while passing through Trebizond in April 1404 and wrote