The Byzantine Senate or Eastern Roman Senate (Greek: Σύγκλητος, Synklētos, or Γερουσία, Gerousia) was the continuation of the Roman Senate, established in the 4th century by Constantine I. It survived for centuries, but even with its already limited power that it theoretically possessed, the Senate became increasingly irrelevant until its eventual disappearance circa 14th century.
The Senate of the Eastern Roman Empire originally consisted of Roman senators who happened to live in the East, or those who wanted to move to Constantinople, and a few other bureaucrats who were appointed to the Senate. Constantine offered free land and grain to any Roman Senators who were willing to move to the East. When Constantine founded the Eastern Senate in Byzantium, it initially resembled the councils of important cities like Antioch rather than the Roman Senate. His son Constantius II raised it from the position of a municipal to that of an Imperial body but the Senate in Constantinople had essentially the same limited powers as the Senate in Rome. Constantius II increased the number of Senators to 2,000 by including his friends, courtiers, and various provincial officials.
The traditional principles that Senatorial rank was hereditary and that the normal way of becoming a member of the Senate itself was by holding a magistracy still remained in full force. By the time of the permanent division of the Roman Empire in 395, Praetors' responsibilities had been reduced to a purely municipal role. Their sole duty was to manage the spending of money on the exhibition of games or on public works. However, with the decline of the other traditional Roman offices such as that of tribune the Praetorship remained an important portal through which aristocrats could gain access to either the Western or Eastern Senates. The Praetorship was a costly position to hold as Praetors were expected to possess a treasury from which they could draw funds for their municipal duties. There are known to have been eight Praetors in the Eastern Roman Empire who shared the financial burden between them. The late Eastern Roman Senate was very different from the Republican Senate as the offices of aedile and tribune had long fallen into abeyance and by the end of the 4th century the quaestorship was on the point of disappearing, save as a provincial magistrate. The Emperor or the Senate itself could also issue a decree to grant a man not born into the Senatorial order a seat in the Senate. Exemption from the expensive position of praetor would also often be conferred on such persons that had become Senators in this way.