The empire of Trebizond takes its place in this great tragedy of history when the end is already in view. In the same year and the same month in which the Latins took Constantinople and the nobility of the imperial capital fled to the cities of Asia (April 1204), two youthful scions of the illustrious House of Comnenus appeared at the head of a body of Georgian mercenaries before the gates of Trebizond. The Comneni, whose name perhaps reveals an Italian origin, emerge into the light of history in the latter part of the tenth century, from a private station among the Greek nobility of Asia, where their hereditary estate was situated near Kastamuni, a town in the interior, which one may reach at the present day by a carriageable road from the port of Ineboli on the Black Sea. Manuel Comnenus, the first to bring fame to the family, was prefect of all the East under the Cæsar, Basil the Second (in 976); and his son, the scholarly Isaac Comnenus, was chosen by his contemporaries to occupy the imperial throne. The nephew of Isaac, the Emperor Alexius Comnenus (r. 1081-1118), is well known for the part which he played during the crusading era; and he was followed on the Byzantine throne by two of the most martial figures of that age of heroes, Kalo-Joannes (r. 1118-43) and Manuel (r. 1143-80). Manuel was succeeded by his cousin Andronicus Comnenus (r. 1182-85), an emperor who did much to purify the corrupt provincial administration of the Byzantine monarchy, and who perished in a domestic revolution, due to his severe measures against the high nobility. The murder of this prince was followed at no long interval by the Latin conquest of the capital; and the two Comneni who came to Trebizond in 1204 were sons of Manuel, son and heir to Andronicus, who had also perished in the aforesaid revolution. Their names were Alexius and David; and they were assisted in their enterprise by their paternal aunt, Thamar, the offspring of their grandfather and a Georgian lady. The political condition of Trebizond during the interval between the murder of Andronicus and the Latin conquest of the capital is not definitely known; but the Greek city was probably feeling the pressure of the neighbouring kingdom of Georgia at the time of the advent of the two Greek princes. The prospects of relief, on the one hand, from this pressure, and, on the other, from dependence upon the rotten court of Constantinople under the hopeful rule of an illustrious family, must have operated as powerful inducements to the townspeople to welcome the new régime. Alexius Comnenus is accepted as master of the city, and his rising fortunes attract to his victorious standard some of the noblest of the refugees from the capital, flying into Asia before the Latins. Others range themselves round the person of Theodore Laskaris in Bithynia; and two rival Greek or Roman empires are established upon Asiatic soil, that of Nicæa, or Nice, the capital of Bithynia, and the empire of Trebizond.