Urth Orthodox is the Mirror of Faith. They are the core of the Universal Church of the Celestial Sun, seeking to hold people to the sanctified truths of the Prophet Zebulon. As the largest sect, it is the Orthodoxy that most people associate with the Church. Its priests can be found on all worlds from the ostentatious bishops of the capital cities to the more humble parish priests in the most poverty-stricken fiefs.
Established by Palamedes Alecto after the Prophet's Martyrdom the Church was able to rally Humanity against the Ukar in the Human-Ukar war. This established the powerbased that continued through the Second Republic, where at the verge of its collapse was declared the official religion of the Second Republic in an attempt to stave off collapse. This gave extreme political power to the Church as it now meant all other religions were illegal. Since then it has grudgingly shared its power with other groups, ceding them spiritual authority in areas they had little interest or resources.
While the Orthodoxy has gained a reputation for its cunning political manoeuvres, most priests know little of such things, being entirely too busy protecting the souls of the simple faithful. Of all churches the Orthodoxy is the most in touch with the populace as they share in their every day lives and their complaints. With their political prestige they are often one of the only groups who protect the interests of serfs from the nobility and league. While many may spurn the Orthodoxy for its martial role in the Emperor Wars, when tragedy strikes, it is the Orthodoxy to which they turn to.
The Urth Orthodox has always been the regular hierarchy of the Universal Church of the Celestial Sun, and Church Patriarchs, except for the rare Amalthean, have always been Orthodox.
The Orthodox clergy is divided into Red and White prieshoods, with the Red clerics under an oath of celibacy, while White clerics can marry. Most Orthodox clerics above the rank of priest are from the Red priesthood.
Most Church bishops and archbishops are Urth Orthodox, as well as most of the Universal Church's rank-and-file clergy (novitiates, canons, deacons, and priests.
The Mahayana wing of the Urth Orthodoxy actually is partially descended from liberal, non-Orthodox sects of the Universal Church from the Diaspora and Second republic eras. After the fall of the Republic (4000), the more conservative and fundamentalist Church leaders among the Orthodoxy, Inquisition, and Temple Avesti persecuted the liberal Church sects for heresy and their clergy absorbed into the Orthodoxy or forced to join Hesychast Monasteries.