Aesedra, by tradition, is an hereditary monarchy and the holder of the office is the world's most powerful person. Throughout its almost twelve thousand year history it has been presided over by an Emperor (or Empress), with inheritance being lineal primogeniture. That is to say, the Heir Apparent inherits the Throne regardless of gender. There have been many Empresses of Aesedra and most have been competent rulers, arguably more so than the males.
At times of crisis, the Council of Prefects have met to appoint an Emperor, usually to resolve a question of precedence (as with the Compromise of 11135) or where there are no heirs at all, as what happened upon the death of Colsis XX Powyvest in 10970.
The role of the Emperor is both authoritative and ceremonial. He or she is classically described as the “Glorious Navigator” in keeping with ancient belief that Aesedra runs herself with the Emperor merely steering her through time. Power is shared in a complex constitutional arrangement between the Emperor, the Council and the provinces.