Manuel III (1364 - March 5, 1417) Grand Comnenus and Emperor of Trebizond. He become the successor of his father, Alexius III in 1377, after the death of his elder brother Basil. In the same year he married Gulkhan-Eudocia, his brother's Andronicus widow, a daughter of King David IX of Georgia. His second wife, married in 1395, was Anna Philanthropene of the Byzantine Ducas family.

He assumed the throne in 1390. With the arrival of the Central Asian conqueror Tamerlane into the region, Manuel allied with him and became his vassal. Tamerlane demanded that Manuel himself and his army join him in the coming war with the Ottoman Turks, but somehow Emperor loosened this demand. The Battle of Ankara in 1402 and defeat of Bayezid I was a considerable benefit to Empire of Trebizond, since the expanding Ottomans were a serious threat to it. However, when Tamerlane left Asia Minor in 1403, part of his army detached from the whole to visit the city of Kerasunt and it was presumably by their ravages that the rule of Melissenos at Oinaion was destroyed. Only the mountains around Kerasunt prevented them from venturing any further, much to the relief of the people of Trebizond. Tamerlane also put his son 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 leaving the Empire and the local Turkmen princes of the region free.

The last years of Alexius' reign were clouded by discord with his own son Alexius IV. Manuel had for a time taken into his service a young man as his page. The favor shown to him, however, aroused the anger of the native aristocracy because of his humble birth so they poisoned the minds of the people against the page. At the same time, Alexius, covetous of the throne, raised the flag of revolt and demanded that the favorite be banished. The nobles joined him and besieged Manuel in the upper citadel, finally forcing him to concede and banish the favorite from the palace. The people then dispersed, but Alexius still ambitious of the crown was forced to be reconciled with his father. Ironically, the price of reconciliation was that Alexius take the young page into his service.

Manuel died in 1417, succeeded by Alexius IV.

The ambassador to Tamerlane Ruy Gonzáles de Clavijo was received by Manuel while passing through Trebizond in April 1404 and wrote the following of him:

The Emperor and his son were dressed in imperial robes. They wore on their heads tall hats surmounted by golden cords, on the top of which were cranes' feathers; and the hats were bound with the skins of martens ... This Emperor pays tribute to Timur Beg, and to other Turks, who are his neighbours. He is married to a relation of the Emperor of Constantinople, and his son is married to the daughter of a knight of Constantinople, and has two little daughters.¹

Manuel, "like his father, took an active interest in buildings of a religious nature. In the year of his succession he presented an ornate cross believed to contain a holy relic (stavrotek), in this case a piece of the cross on which Jesus Christ was crucified, to the Sumela Monastery."²

References

1. Clavijo's Embassy, translated by C. R. Markham (1859), quoted in The Last Centuries of Byzantium, 1261–1453, by Donald M. Nicol (1972).
2. From an article on the website of the Turkish Ministry of Culture and Tourism about the Sumela Monastery, retrieved December 28, 2004.