Raised at the time of the fourth founding, the Order of Sanguinius one of the very few chapters of this period to use the Blood Angel’s geneseed. The most ancient of the chapter’s records tell that the chapter was formed at the petition of the Blood Angels Chapter Master of the era, Lord Durata.
Aware of the gradual degeneration of the Blood Angels own geneseed, the Blood Angels Apothecaries used the most ancient geneseed samples, samples that had lain in the stasis vaults since before the Horus Heresy, and rumoured to even predate the Great Crusade.
Unusually for a successor chapter, the creation of the Order of Sanguinius was overseen directly by their parent chapter. As such, the initial history of this chapter merges into the legends of the Blood Angels themselves, although over seven millennia as a separate military unit, the Order of Sanguinius has a long and glorious history of its own.
The chapter is unusually secretive even for the Astartes. There is very little information regarding the home world or recruiting practices of the Order. It is known that the Rance Agreement bound the chapter to the service of the Ordo Mallus on several occasions over the past 1200 years.