Krites

The Byzantine Empire had a complex system of and bureaucracy, which was inherited from the Roman Empire. At the apex of the hierarchy stood the emperor, who was the (autokrator) and who was considered to be divinely ordained. Beneath him, a multitude of officials and court functionaries operated the complex administrative machinery that was necessary to run the empire. In addition to those officials, a large number of honorific titles existed, which the emperor awarded to his subjects or to friendly foreign rulers.

Over the more than thousand years of the empire's existence, different titles were adopted and discarded, and many lost or gained prestige. At first the various titles of the empire were the same as those in the late Roman Empire. However, by the time that Heraclius was emperor (610–641), many of the titles had become obsolete. By the time of Alexios I reign (1082–1118), many of the positions were either new or drastically changed. However, from that time on they remained essentially the same until the fall of the Byzantine Empire in 1453.

In the early Byzantine period (4th to early 7th century) the system of government followed the model established in late Roman times under Diocletian and Constantine the Great, with a strict separation between civil and military offices and a scale of titles corresponding to office, where membership or not in the Senate was the major distinguishing characteristic. Following the transformation of the Byzantine state during the 7th century on account of massive territorial loss to the Muslim conquests, this system vanished, and during the "classic" or middle period of the Byzantine state (8th-late 11th centuries), a new, court-centered system emerged. In this, the new titles derived from older, now obsolete, public offices, and dignities of a certain level were awarded with each office. A senatorial class remained in place, which incorporated a large part of the upper officialdom as every official from the rank of protospatharios (Literally "first sword-bearer;" originally the head of the Emperor's bodyguards) was considered a member of it. During this period, many families remained important for several centuries, and several Emperors rose from the aristocracy. Two groups can be distinguished: a metropolitan civil nobility and a provincial military one, the latter remaining regionally based and having large land-holdings, but apparently no military forces of their own, in contrast to contemporary Western Europe.

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