Foundation

The Ordo Hereticus was founded much later than the Ordo Xenos and Ordo Malleus, created after the Age of Apostasy which occurred during the second century of the 36th millennium. The Apostasy and the many heresies that took root during the anarchy (most notably the Plague of Unbelief), had severely destabilized the Imperium in a way not seen since the Horus Heresy.

The Ordo Hereticus was formed as a check on the Ecclesiarchy, ensuring that another man like Vandire could not gain the level of power and control he did. Although the Ecclesiarchy has its own internal regulatory bodies, it is still the role of the Inquisition to monitor all organizations of the Imperium, including the Ecclesiarchy.