By this means it was able to defy both the Seljuks and the Ottomans, and to maintain its independence against the emperors of Nicaea and Constantinople.
From time to time the emperors of Trebizond paid tribute to the Seljuk sultans of Iconium, to the grand khans of the Mongols, to Timur the Tatar, to the Turkoman chieftains, and to the Ottomans; but by means of skilful negotiations they were enabled practically to secure their independence.
In 1516 the Ottomans took it from the Egyptian Mamelukes.
In 1464 it was taken by the Ottomans; and after being in Venetian possession in 1690, was restored to them in 1691.
Under the new regime this system, which had greatly cramped the military strength and efficiency of the Ottoman Empire, has been changed, and all " Ottomans " are now subject to military service.