The Alessian Order can trace its origins to the prophet Marukh, who preached of a Single God and questioned the legitimacy of Elven rule. This depiction of a Single God became increasingly abstract and unknowable, as the Alessians realised they had to incorporate existing ancient polytheistic elements into their new religion for it to find a wide acceptance. This eventually led to the Order declaring itself the authority on every religion in Tamriel, leading to a massive growth in power and influence.
The Order's concept of the One was rooted in the belief that the God of Time Akatosh is of unitary essence, as proven by the monolinearity of Time. Furthermore, they believed that his sibling Shezarr is "singularly misplaced" and therefore doubly venerated. Their hatred of all things Elven was such that they could not accept that their Supreme Spirit Akatosh was also the Elven High God Auriel.[UOL 1]
The Order therefore believed that their purpose upon Mundus was to "reverse the error of Sanctus Primus" and "restore Ak-at-Osh to humanadic purity" by exorcizing the Elven elements of Auriel (the "Aldmeri Taint") from Akatosh. A group known as the Maruhkati Selectives were chosen to perform the ritual dance to carry this out. However, their dance instead resulted in a Dragon Break known as the Middle Dawn, a period of non-linear time said to have spanned one thousand and eight years.
When the War of Righteousness broke out in 1E 2321, the Alessian Order's great monastic complex at Lake Canulus was razed, destroying most of their records. The Order collapsed within ten years, ending their theocratic rule. However, veneration of the One continued. The Temple of the One in the Imperial City remained standing, housing the Dragonfires and acting as a temple to the Eight Divines and later Nine Divines. Tiber Septim revived the ancient Temple of the One cult when he became Emperor, and expected his subjects to join it.
During the Imperial Simulacrum in the late Third Era, two widespread temples called the Brotherhood of the One and the Conclave of the One both venerated this deity. The Brotherhood had parishes in city-states such as Lilmoth and Shornhelm, and in smaller settlements like Neugrad Watch and Wasten Coridale. The Conclave on the other hand was seen just as widely in city-states such as Alabaster and Necrom, and in minor settlements like Belkarth Guard and Longhaven.
- Pocket Guide to the Empire
- Glenumbria: Alessian Orders
- The Exclusionary Mandates
- Vindication for the Dragon Break — Fervidius Tharn, Arch-Prelate of the Maruhkati Selective
- Where Were You ... Dragon Broke — Various
- Cleansing of the Fane
- Father Egnatius' dialogue in ESO
- Jeelius' dialogue in Oblivion
- Martin Septim's dialogue in Oblivion
- The Real Barenziah, v 3 — Anonymous
- Brotherhood/Conclave of the One temples in Arena
- The Prophet's dialogue in Knights of the Nine
Note: the following references are not from official sources. They are included to provide a rounder background to this article, but may not reflect established lore.