His successes as a soldier were many and important. One of the first of his conquests was to put an end to the empire of Trebizond. As its history and decay played an unimportant part in the destruction of the Greek empire, it has been unnecessary to give an account of this pretentiously named State. It had occupied a narrow strip of land along the southern shore of the Black Sea, of varying length, from a point near Batoum towards the west, on one occasion stretching to within sight of the Bosporus, but never including either Amassus or Sinope. Its population, though Greek-speaking, was mostly composed of Lazes. [Sidenote: Summary of its history.] When the Latin invaders were on the point of capturing Constantinople, two young Greek princes had escaped to Trebizond, defeated the Byzantine governor, and one of them, named Alexis, was acclaimed emperor. He took the title of Grand Comnenus and Emperor of the Faithful Romans. It seemed for a short while as if he, instead of Theodore Lascaris at Nicaea, might take the lead of the Greek peoples, and indeed Theodore had to arrange with the sultan of Konia--or, as he called himself, of Roum, that is, of the Romans--to prevent Alexis from attempting to extend his territory to Nicaea. But the power of the Trebizond empire did not increase, although the city from which it took its name became large, wealthy, and populous. Even before 1228 it had become tributary to the Seljuk sultan and so continued till 1280. A series of more or less uninteresting and incompetent emperors and empresses continued to hold a semi-independent position, amid alternate intrigues and struggles with Turkoman and Turkish tribes, and fierce fights with the Genoese, until the advent of Timour. The emperor of Trebizond, as in later years he called himself, consented to become the vassal of this great leader, and agreed to send twenty ships to join a like number which the Greek emperor was to prepare at Constantinople to attack Bajazed. The defeat of the Ilderim at Angora rendered such joint action unnecessary. When Timour retired, Trebizond languished until its territory was little more than a small district around the capital. It was first attacked by the Ottoman Turks in 1442, and made a successful defence. After the capture of Constantinople, the emperor John consented to become a tributary prince of Mahomet, but shortly afterwards attempted to unite the emirs of Sinope and Caramania and the Christian kings of Georgia and Lesser Armenia in a league to attack his suzerain. Before anything could be done, John died, and when Mahomet, in 1461, having subjugated the Greeks in Morea, turned his attention to Trebizond, no allies were ready to aid David, the new emperor. A great expedition of sixty thousand cavalry and eighty thousand infantry was led by Mahomet himself to David’s capital, while a large fleet co-operated with the army. The alternative was given of massacre or submission.