The Ecclesiarchy is the formal church of Ahm, who administer the laws of the Writ of Ahm. They are officially only responsible for spiritual administration, but since the disappearance of the Empress, they have taken over the secular administration of Resotania as well.
The Ecclesiarchy is not generally held to be every single Bishop, Priest, and Voice, but instead refers to the core that reside in Resotania and make decisions as to the structure of the church and the faith. They are led by Archbishop Fiora Eltal XXIII.