All Panaretos tells us about his short reign is that Bayram Beg, the Emir of Chalybia, invaded Manuel's territory with his Turkmen, penetrating as far as Asomatos, where the Trapezuntine army defeated them on 30 August 1332, inflicting many casualties and capturing many of their horses.

The Byzantine party invited Manuel's uncle Basil to return to Trebizond from Constantinople and to take over the government.

However, an unsuccessful revolt led by the megas doux John in February 1333 prompted his uncle Basil to order Manuel's execution.

Of the four Emperors deposed during the existence of the Empire of Trebizond, Manuel was the only one to be killed after being removed from power; in the other three cases, it was sufficient that the former ruler be exiled.

[4] Further, during the existence of the Byzantine Empire execution of underage rivals for the Imperial throne was rare; even the ruthless Michael VIII Palaiologos was satisfied with merely blinding the deposed and imprisoned John IV Laskaris, who was about Manuel's age.