Moirae Schism

The Moirae Schism was one of the most divisive and widespread doctrinal conflict to afflict the Adeptus Mechanicus since the Horus Heresy. The schism erupted during the widespread civil strife of the Nova Terra Interregnum in the early years of M35, and this factor allowed the swift spread of radical doctrines that would perhaps have been quickly quashed in a more stable period of the Imperium's history. Even with the destruction of the minor Forge World of Moirae, the source of this heretical doctrine, by a large fleet despatched by Mars, violence will still flare up intermittently between the orthodox and radical factions for the next millennium before the schism was finally ended.

History
During the early years of the 35th Millennium, the Imperium was divided in half after the rebellious Ur-Council of Nova Terra dismissed the authority of the High Lords of Terra and claimed separate rule over the Imperium's Segmentum Pacificus. This was a period of division and civil war in which the Imperium became fractured into warring and disparate factions which cut across the lines of the Adeptas and turned former allies against each other. During this period it was not just the Imperium's governance and religion which suffered schism, the Adeptus Mechanicus was also afflicted with division and internal warfare brought about by doctrinal differences and competing powers. One of the most acrimonious of these conflicts was the Moirae Schism, a dogmatic battle between Martian Orthodoxy and a radical creed based upon the prophetic writings of a triad of tech-mystics based on the minor forge world of Moirae.

The Moirae tech-creed was based on the prophetic wave calculations of a triad of tech-mystics enshrined within Moirae's colossal data-looms who believed that they had discerned a series of predictive patterns within the micro-fluctuations of the Astronomican beacon. These Gematric patterns they believed contained the word of the Omnissiah-God-Emperor from which the skein of future history and humanity's destiny could be read. They compiled the fruits of their apocalyptic divinations within encrypted archives, copies of which quickly spread through many of the Cult Mechanicus' sects. These radical teachings included among other visions and interpretations of the Emperor's will, veiled references to the future overthrow of Mars and the fusion of the Cult Mechanicus and the Ecclesiarchy into a unified whole. Such claims were treated (unsurprisingly) as dark sedition by the Mechanicus authorities on Mars and civil war was quickly sparked between traditionalist and radical elements. One of the first casualties of the conflict was the forge world of Moirae itself, which was reduced to a cinder by Mars' ruling Fabricator-General's rectification fleet. But by this time the schismatic creed had spread. The disruptive creed quickly gained influence, both within sects of the Mechanicus priesthood as well as a number of tech guard regiments and Titan Legions causing untold harm, before being transmitted even further afield to Space Marine Chapters with close ties to the Adeptus Mechanicus -- and in this the Iron Hands were no exception.

The Moirae doctrines were quickly embraced by a significant percentage of those within the Chapter. Discord soon followed, and the Iron Hands rapidly approached the edge of a full civil war, an event only averted by the Iron Hands Great Clan Council's intervention to impose a settlement. Notoriously straightforward and harsh, their solution taken to avoid mass bloodshed within the ranks was a simple one - exile for the minority who had embraced the dissident doctrine, and a binding treaty never to raise their hands against their former brothers enacted by both sides. It is believed that fully a third of the Iron Hands brethren then departed, to be joined in time by a handful of other Space Marines from other Iron Hands Successor Chapters who shared their beliefs (although evidence exists that some such as the Red Talons mercilessly destroyed their errant brothers over this matter, rather than suffer the dissidents to live). Though the exiled faction considered themselves as wholly part of the Imperium, they were a force apart from their Progenitors, who treated the exiles with cold indifference at best and utter contempt at worst.

Thus, matters continued until the dawning of the Age of Redemption. During this period the newly resurgent High Lords of Terra re-ssembled the disparate strands of anarchy and purged what could not be saved from the Imperium. The Moirae exiles of the Iron Hands, now a separate Chapter in all but name were weighed and judged, their record examined in minute detail as was their gene-seed for unworthiness or deviance and they were found to be loyal and untainted. As a result by an almost unique edict the newly renamed Sons of Medusa were reorganised and ratified as a Chapter of the Adeptus Astartes within the Emperor's grace.

Conflict between the advocates of the Moirae doctrine, the Martian Orthodoxy and other opposing radical groups would continue to flare up intermittently throughout the next millennium before the schism was finally ended and its surviving adherents brought back into the Cult Mechanicus' fold.