An empire on the northern coast of the Black Sea (Gr. Pon- tos), with its capital at the thriving city of Trebizond (mod. Trabzon, Turkey) from 1204 until 1461. Although its foundation was not a direct consequence of the capture of Con- stantinope (mod. Istanbul, Turkey) by the Fourth Crusade in 1204 (as was the case with the Empire of Nicaea and the despotate of Epiros), the Empire of Trebizond is often considered as one of the three main successor states of the Byzantine Empire following the Latin conquest.
The empire was founded when two grandsons of the last Komnenian emperor of Byzantium, Andronikos I (d. 1185), namely the Megalokomnenoi (“Great Komnenoi”) Alexios I (1204-1222) and David (d. 1212/1213), seized Trebizond from its Byzantine duke, Nikephoros Palaiologos, with the help of their aunt Tamar, queen of Georgia, in March or early April 1204.
For most of its history the new state was cut off from the main Byzantine centers at Nicaea (mod. Iznik, Turkey) and Constantinople and was restricted to a narrow strip of land along the southeast Pontic littoral. Its main coastal centers were Kerasous (mod. Giresun, Turkey), Oinaion (mod. Ünye), Amisos (mod. Samsun), and Sinope (mod. Sinop). Its chief inland centers were Bayberdon (mod. Bayburt), Neocaesarea (mod. Niksar), Amaseia (mod. Amasya), and Payrae (mod. Bafra), while its two celebrated monastic centers were those of Soumela and Vazelon.
Although not directly involved in the crusades, the empire holds a particular place in Anatolian affairs in the late Middle Ages, with its twenty-one rulers claiming the imperial Byzantine title until 1280/1282 and thereafter the title of basileus and autokrator (both reflecting Byzantine imperial usage) of all the East, the Iberians (i.e., Georgians), and Perateia.
The empire’s initial years were consumed in fratricidal strife with the rival empire of Nicaea and in attempts to ward off attacks from the Saljûqs of Rūm, who took Sinope in 1214 but failed twice before Trebizond itself (1205/1206 and 1222/1223). For much of the remainder of the century, the empire was in a state of vassalage to the Rūm sultanate and (from 1243) to the Ilkhanids. However, with the decline of the sultanate, the empire was frequently attacked by Turcomans, especially the Ak-Koyunlu (White Sheep) confederacy, from the 1340s onward, and in the late fourteenth and early fifteenth centuries, the Grand Komnenoi pursued a consistent policy of marriage alliances with Georgian and Turcoman dynasties. Alexios II (1297-1330), Michael (1344-1349), and Alexios III (1349-1390) were also forced to grant commercial privileges to the Genoese and Venetians. However, the most menacing adversary was the Ottoman sultanate. John IV Kaloioannes (1429-1458/1460) was forced to acknowledge Ottoman suzerainty in 1456, and after a long Ottoman siege by land and sea, the last Trebi- zondine ruler, David I (1458/1460-1461), was forced to capitulate on 15 August 1461 and surrender his capital to Sultan Mehmed II. The execution of David and his male descendants in 1463 shattered any future attempts to restore the Grand Komnenian Empire.