- "The false god cursed us and denies the rightful place of our gods. Let us ascend the heavens themselves and burn his empire until nothing remains but dust."
- —Luthor Straab, Champion of Chaos Undivided
The Angels of Purity were once fanatically loyal to the Imperium and merciless to it's enemies. But, like all other Blood Angel Successors, it was only a matter of time before they fell under the curse of the Black Rage . After centuries of locking up battle brother after battle brother, the Angels of Purity believed themselves to be cursed by the Imperium, that they were in fact the evil of the universe and not, as they were told, the Great Enemy . They were eventually excommunicated by the Imperium after they launched an attack on a Balck Templar Fleet, destroying several of their vessels in the process. They are noted by Loyalist Chapters as savage and fanatical in their beliefs, and an unrelenting force that needs to be purged from the galaxy.
The Angels of Purity were created during the 23rd Founding, and were founded on the planet Peritus III, a Civilised World whose population mirrored that of the Puritans, highly religious people who punish the sinful and evil. Torture and public executions were common amongst the populus. When the Imperium of Man first came into contact with the planet, the people there worshipped the Emperor as their god and the Space Marines his angels, come to elevate them for their faith and belief. The people of Peritus III were, indeed, granted their wish and the chapter was born, made from the geneseed of the Blood Angels chapter. These Marines came to call themselves the "Angels of Purity" as a sign of their undying faith and dedication to their God Emperor.
Pre-RenegadeThe Battle Brothers of the Chapter quickly became a force to be reckoned with, their abundance of fanatical followers and their relentless attacks made them amongst the most vicious chapters of the Adeptus Astartes. Although not as disciplined as some other Chapters, such as the Ultramarines or Imperial Fists, they made up for their lack of tactics with pure ferocity and relentless attacks.
However, as the centuries went by, members of the Chapter began to succumb to the Blood Angels curse, the Black Rage. At first, many took this as demons possessing their Battle Brothers and they were locked in the Tower of Solace, a tower built to punish the wickid, and burnt to death to exorcise the evil spirits. In time, the Chapter began to realise that the madness only afflicted their own members and not the general populus of Peritus III. They began to draw the conclusion that the Imperium of Man had infact cursed them, and decided that they were in fact demons, not gods as they previously believed.
With the realisation of their affliction, the Chapter concluded that the Imperium's most hated enemies must therefore be the force of good, and attempted to make contact with the forces of the Ruinous Powers. Their prayers were answered by a Dark Apostle of the Word Bearers legion known as Erasmus. He told the Chapter of the Gods of Chaos , telling them that they are the true gods, that the Imperium of Man twists the reality of their nature, that demons were infact the true angels and that the powers of Chaos could truely elevate them and free them of the curse given to them by the Adeptus Astartes. The Angels of Purity readily agreed to this offer but were asked to show the Gods of Chaos a gesture of true faith. They did so by sending out a distress beacon alerting the Imperium of the Chaos presence. In response, a small fleet of Black Templars were sent to Peritus III to irradicate the Chaos forces, but before they were able to open fire on the Word Bearer's ship (which was purposely left empty of any crew), the Angels of Purity opened fire at the fleet in a surprise attack. With this act of heresy, the chapter was declared Excommunicate Traitoris and joined the forces of Chaos.