Despite Ziragshabdar’s successful efforts to rebuild the government system of Parsumash, she never had the drive to create a centralized religion authority, so, upon her death, leadership mostly fell to the individual mobads in a region. while under the Haxamanids, this wasn’t of much consequence, after the Yauna invasion, and the consequent seeping of their cultural influence into Equestria, this led to a proliferation of different intepreretations of the Mazdayasna, the foremost of them being the so-called ‘Zurvanite’ interpretation, that combined Yauna and Asorian philosophies and theology with the traditional religion, named after Zurvan, originally the goddess of time and fate in the Pre-Ziragshabdarian unicorn religion, and progenitor for both Ahura Mazda and Angra Mainyu to the Zurvanites.

This decentralized period ended with the ascension of the Sasanids, originally chief mobads of Pars, with one of the first priorities of Ardashir being the establishment of a Mazdayasnan orthodoxy, which would turn out to be decidedly non-Zurvanite. with this, also ensued the creation of the mowbedan-mobad office, wich would be the religious head from then on, the post being given to the legendary Setaresuvirles Balmeth. The post would remain in mortal hands until 488, when Shahanshah Celestia was given the post and has retained it ever since.

Meanwhile, in Tisbon, a pegasus named Mani had her first revelations, which would be further elaborated in the following years. The faith that she created, which the Equestrians call Azadaena, mixed elements of Zurvanism, Salomeanism (a apocalyptic Israelite cult established by a Salome bat Maryam two centuries before), and Aryavartan philosophies. Despite her decidedly heterodox philosophy, she eventually became a friend of the then Shah, Shadokht I. This allowed her to attempt to preach her religion without interference from the government, but after Shadokht died, her daughter Warahran, who was close to Mani’s rival Kartir, Setaresuvirles’ successor as mowbedan-mobad, procceeded to imprison Mani and began persecuting her followers. However, Mani escaped and established herself in Hrom, and began preaching there.

At the time, the traditional religions of Hrom and the Yauna were decaying, and as such, Mani soon managed to acquire a greater number of followers in Hrom than she ever had in Equestria. However, even then, the faith was still subjected to periodic persecution, until the second century, when, starting with Constantina, the empresses began favouring them, eventually culminating in Theodosia making it the official religion of the empire in 210.

However, as the religion embedded itself into the state apparatus, it started being modified by it, slowly losing the more mystical trappings, simplifying its cosmogony, and establishing a unified creed for itself, all of which would enable it to survive in the far west after Hrom’s authority collapsed there.

However, the religion still doesn’t have a proper central authority, with the authority being held by the matriarchs of the six major sees - Roma, Cartago, Constantinapolis, Antiochia, Jerusalem and Alexandria. Even if the population of latter three dioceses is majoritarily Mazdayasnan these days.