- Child of Nirn ponder, which would you choose: tyranny of mages, restricting spell use, or necromancy, communion with thy dead, ancestors returned, generations reunited? — Worm Saga
The Order of the Black Worm is the cult led by Mannimarco which is devoted to necromancy. Those outside the Order sometimes call it the Cult of the Black Worm or the Worm Cult, although the organization was officially known as the Fellowship of Anchorites during its brief Imperial charter. Being the most infamous practitioners of necromancy, they are colloquially known as The Necromancers. While Vanus Galerion formed his Mages Guild in the early Second Era, Mannimarco secretly formed the Order in its shadows. Their many dark accomplishments include the great battle where Galerion was killed, aiding the forces of Molag Bal during the Planemeld, and numerous plots against the Mages Guild, including an attempt during the Oblivion Crisis which resulted in the apparent death of Mannimarco. Members and servants of the cult are often branded with a black pentagram, to symbolize the damnation of their souls.
The Order of the Black Worm arose as Mannimarco recruited mages to form a series of cells, known as Worm Nests, each led by a Worm Anchorite, who supervised adepts, Worm Warriors, and thralls. New cultists were attracted by promises of great power for those who served loyally, and all were sworn to secrecy on pain of undeath. The Anchorites reportedly communicated with Mannimarco directly, though how they did so is not clear. Some, known as Worm Eremites, decided to become undead themselves, and were always guarded by undead minions.
Archmage Galerion sought to root out and destroy these cells, but Mannimarco proved adept at recruitment. He sought out mages from within the Guild, outcast witches, and Reachmen wizards to bring into his underground, illicit Order. In most places in Tamriel, necromancy was considered an atrocity, but many officials proved susceptible to bribery or other influences, and turned blind eyes as the black-robed Order established stronger footholds in their domains. Members of the Order reputedly never spoke Mannimarco's name aloud, referring to him only as the King of Worms.
Galerion attributed the proliferation of soul gems and soul trapping to the influence of the Order. Soul trapping had been taught only to the most experienced and dependable mages of the Mages Guild, both because of the potential for abuse and because it was technically a subset of necromancy. Nevertheless, it became common knowledge in the emerging community of mages, apparently as part of the Order's plot to make necromancy seem commonplace. Despite Galerion's attempts to co-opt the practice of soul trapping, ferret out cells of the Order, and generally diminish their influence, the practice of necromancy became accepted as a valid, and legally tolerated, magical discipline in some places around Tamriel, notably Cyrodiil.
During the Alliance War circa 2E 582, the Order aided Mannimarco in sinister plots across Tamriel. In so doing, they also aided Molag Bal (perhaps why they were sometimes referred to as a Daedric cult). When Empress Clivia Tharn fell under Mannimarco's sway, the Order was allowed to operate freely in Cyrodiil. The Mages Guild was ejected from the city, and the Order took their place in the Arcane University and as advisers to the Ruby Throne. From there, they set their sights on replacing the Guild across the entire continent. There were even rumors that they sought to ally themselves with the Sload of Thras. Abnur Tharn, High Chancellor of the Elder Council, became one of the leaders of the cult.
In the time of the Imperial Simulacrum, members of the Order searched various provinces attempting to collect artifacts. There were reports of the cult pursuing an individual who knew how to find Spellbreaker, and offering large sums of gold to a person who had information about the Staff of Magnus. The Order became more prominent in the events leading up to the Warp in the West in 3E 417, when they were involved in various political schemes in the Iliac Bay area. They were based in Scourg Barrow, where Mannimarco plotted to obtain the Totem of Tiber Septim. The order allied itself with several important figures, such as Lord K'avar and Princess Morgiah.
Following the Warp, the Order no longer knew Mannimarco as the King of Worms, for he had become their God of Worms. They came to believe that he had ascended to become the Necromancer's Moon, or the Revenant, and that he would deliver them from the Day of Reckoning. They established altars that, when struck by the light of the Necromancer's Moon, converted grand soul gems into black ones that are capable of trapping the soul of a sentient mortal.
- Guild Memo on Soul Trapping by Vanus Galerion, Archmagister Emeritus — Vanus Galerion's proposal on the use of soul-trapping magics
- I was Summoned by a Mortal by Kynval Zzedenkathik of Clan Deathbringer — A humorous tale of a Dremora's summoning
- Necromancy in Modern Tamriel by Wafimeles Masteret (Lorekeeper) — A treatise on the current state of necromancy in Tamriel
- The Order of the Black Worm by Evoker Brucille — Mages Guild Report: The Order of the Black Worm
- Worm Saga by Mannimarco — Rhyming autobiography of Mannimarco
- Necromancy in Modern Tamriel — Wafimeles Masteret (Lorekeeper)
- Aniaste's Journal — Aniaste
- Chancellor Abnur Tharn Answers Your Questions 2 — Chancellor Abnur Tharn
- Necromancer's Moon
- Events of Oblivion
- Events of Arena
- The Order of the Black Worm — Evoker Brucille
- Guild Memo on Soul Trapping — Vanus Galerion, Archmagister Emeritus
- Auridon Explored, Chapter IV — Fenlil the Wayfarer
- Events of ESO
- Chronicles of the Five Companions 4 — Abnur Tharn
- Aldimion's Journal — Aldimion
- Events of Daggerfall