Trebizond, at the southeast corner of the Black Sea, is the capital of the last remnant of Greek empire.

Although subject to brief periods of domination by the neighboring Seljuq Turks, Mongols, and the Greeks of Nicaea or Constantinople, the Empire of Trebizond had been largely bypassed by both the Seljuqs and the Mongols because of its relative isolation, difficulties of access, and conflict among its enemies.

Its prosperity lies partly in export of its own products—silver, iron, alum, cloth, and black wine—and partly from taxes on transit trade to western Iran.

After the Fall of Constantinople to Mehmed II in 1453, Trebizond and the Morea were left as the last remnants of the Greek imperial tradition.

Mehmed II had immediately summoned Emperor John IV of Trebizond to pay tribute in Constantinople and imposed heavy tolls on Trapezuntine and Venetian shipping through the straits.

John had apparently failed to cooperate, and in 1456 the Sultan dispatched his governor of Amasya, Hizir Bey, to attack Trebizond by both land and sea.

According to the contemporary historian Laonikos Chalkokondyles of Athens, Hizir raided the countryside, even penetrating into the marketplace of Trebizond, capturing altogether about two thousand people.

The city, deserted due to plague, is likely to fall; John makes his submission and agrees to pay an annual tribute of two thousand gold pieces in return for the return the captives Hizir had taken.

John IV of Trebizond had sent his brother David to ratify the treaty before Mehmed II himself, which he does in 1458, but the tribute is raised to three thousand gold pieces.

An alliance with the powerful Aq Qoyunlu tribe, who are the Ottomans' most powerful rival, appears more than beneficial.

Trebziond and the Aq Qoyunlu have a history of cooperation.

The-great aunt of John IV of Trebizond, the reigning emperor, had married Qara Osman, emir of the Aq Qoyunlu.

Uzun Hassan eagerly agrees to be the protector of Trebizond, as well as making other concessions, in return for the hand of John’s daughter Theodora, who is widely famous for her great beauty.

News of the Princess of Trebizond as the consort of the powerful Uzun Hassan will spread to the West, and helps to foster stories of Princess of Trebizond.

However, this alliance will fail to help John's successor, his brother David.

Mehmet had gradually annexed the last Palaiologian possessions in the Morea, completing the task with the conquest of Mistra on May 29, 1460.

Mehmed marches on the imperial city of Trebizond in 1461.

Uzun Hassan initially supports the Trapuzentines, but he is persuaded by the Ottomans to abandon the effort.

After securing the eastern border, Mehmed attacks Trebizond, whose last emperor, David Megas Komnenos, finally surrenders to Mehmed on August 15, 1461, after a twenty-one-day siege, ending the polity.

The transformation of the Eastern Greco-Roman world into the Ottoman world is at last complete.

The last prince of Lesbos is carried off to Constantinople as a captive, along with most of his family.

Here he converts to Islam and is briefly released.

His sister Maria Gattilusio (widow of Alexander, a brother of Emperor David of Trebizond), who is called the most beautiful woman of her day, disappears into the sultan's harem.

Her son Alexios becomes a page, but seems to have been beheaded not long afterwards.

Mehmed II now discovers that a favorite page of his, who had fled from him some time before, had become Christian and is included among the retinue of Prince Niccolò.

This final indignity seems to have hastened Niccolò's death sentence.

He is strangled to death with a bowstring.