Manuel I Megas Komnenos, ruler of Trebizond from 1238 to 1263, had preserved internal security and acquired the reputation of a great commander, but the empire was already losing outlying provinces to the Turkmen, and found itself forced to pay tribute to the Seljuqs of Rum and then to the Mongols of Persia, a sign of things to come.

The troubled reign of John II (1280–1297) included a reconciliation with Constantinople and the end of Trapezuntine claims to the great metropolis.

Trebizond had reached its greatest wealth and influence during the long reign of Alexios II (1297–1330) but suffered a period of repeated imperial depositions and assassinations from the end of Alexios' reign until the first years of Alexius III, ending in 1355.

The empire will never fully recover its internal cohesion, commercial supremacy or territory.

Manuel III Megas Komnenos, who succeeded his father Alexios III as emperor in 1390, had in 1391 and 1396 confirmed the privileges of the Venetians.

Manuel had come under the overlordship of Timur by 1402, while the Ottoman Turks were encroaching on his western frontier.

Timur had demanded that Manuel and his army join him in the coming war with the Ottoman Turks, but somehow the Emperor had avoided this demand, although he had contributed twenty galleys to Timur's general effort.

The Battle of Ankara in 1402 and defeat of Sultan Bayezid has been a considerable benefit to Empire of Trebizond, since the expanding Ottomans are a serious threat to it.

The rule of the Melissenos family at Oinaion is presumed to have been destroyed by the ravages of part of Timur's army, which detaches from the whole to visit the city of Kerasous when he leaves Asia Minor in 1403.

Only the mountains around Kerasous prevent them from venturing any further, much to the relief of the people of Trebizond.