The Empire of Trebizond or the Trapezuntine Empire was a monarchy that flourished during the 13th through 15th centuries, comprising the far northeastern corner of Anatolia and the southern Crimea. Original formed during a revolt against the usurpation of the imperial throne by the grandsons of Emperor Andronikos I Komneos, Trebizond (current Trabzon, Turkey, with which the name of the empire is a cognate) became a Byzantine Greek successor state established after the fall of the Earner Roman Empire (Byzantine) in the Fourth Crusade, along with the Empire of Nicaea and the Despotate of Epirus. The Emperors of Trebizond pressed their claim on the Imperial throne for decades after the Nicaean reconquest of Constantinople in 1261. The Trapezuntine monarchy survived the longest of the Byzantine successor states. The Despotate of Epirus was slowly decimated, and briefly occupied by the restored Byzantine Empire c.1340, thereafter becoming a Serbian dependency and later inherited by Italians, ultimately falling to the Ottoman Empire in 1479, having long ceased to contest the Byzantine throne. While the Empire of Nicaea had become the resurrected Byzantine Empire, it came to an end in 1453 with the conquest of Constantinople by the Ottoman Empire. The Empire of Trebizond continued until 1461 when the Ottoman Sultan Mehmed II conquered it after a month-long siege and took its ruler and his family into captivity. The Crimean Principality of Theodoro, an offshoot of Trebizond, lasted another 14 years, falling to the Ottomans in 1475.