Ruination Heresy

History
A millennium after their inception during the 13th Founding, the fate of the Blood Vultures' was irrevocably changed, their genetic flaw revealed to all. A hitherto unknown genetic deficiency within their gene-seed somehow inexplicably made some of their battle-brothers susceptible to the corrupting influence of Chaos, causing once stoutly loyal warriors to turn on their brethren. The appearance of this flaw began to manifest itself only a few decades after their creation. Individual battle-brothers, or even whole squads were sometimes infected by this corrupting malady. Those who suffered from this infliction were either imprisoned deep within the bowels of their fortress-monastery on Regark, or sometimes had to be mercilessly put down. The Blood Vultures had worked so hard to conceal this flaw from prying eyes for fear of Inquisitorial sanction. But the events that occurred sometime in the early 37th Millennium, brought their Chapter's genetic flaw to the forefront, revealing to all their secret shame.

This Chaos corruption had not solely affected just the Blood Vultures, but had also been found amongst other Chapters supposedly created during their Founding, but for unknown reasons these specific Chapters remain unnamed in official Imperial records for unspecified reasons. At the height of their first millennial celebration of the Blood Vultures' inception, a whole company of the Chapter renounced their oaths of fealty to the Emperor of Mankind, and proceeded to attack their former brethren during a celebratory processional within Regark's capital city, slaughtering innocent civilians, visiting Imperial dignitaries and military commanders as well as their former battle-brothers.

Led by the former Captain of the Chapter's 3rd Company, known as Teigon 'the Marauder', a brutal and vicious Astartes, the corrupted brethren wreaked as much havoc and bloodshed as they could before their loyalist brethren were finally able to counter-attack and drive their corrupted brethren away from the civilian population. In the ensuing internecine conflict, half of the planet's capital city was utterly destroyed during the fierce conflagration. Though the Blood Vultures managed to kill half of their corrupted brethren, Teigon and his remaining followers managed to effect their escape by utilising teleport homing devices to teleport aboard one of the Chapter's strike cruisers in orbit.

Before they fled the wrath of their erstwhile brethren, the traitorous Astartes performed one last act of spite, and launched a devastating orbital bombardment, destroying the Planetary Governor's palace, and causing the deaths of thousands of innocents. They then made their way towards the nearest Mandeville point and fled into the Warp. When they emerged centuries later, they had become fully corrupted by the insidious touch of the Ruinous Powers, becoming the Chaos Warband known as the Dark Vultures. Since that time, the Blood Vultures have sworn a blood-oath to see their corrupted brethren utterly destroyed, a debt which has yet to be paid.