One hundred and twenty years ago, the ruler of the Terrasan Empire--which had a greater claim to the title of Empire in those days than it does now, convened a quorum of experts on matters occult and theological. While there isn't an official church or religion in the lands of the Terrasan Empire, culturally the people recognize a common pantheon of divine beings who influence the lives of mortals in ways both subtle and--occasionally--less so. Small churches attended by decentralized friars, have sprung up over the centuries all throughout the area to cater to the spiritual needs of the people. While the empire has resisted allowing these churches to centralize too much, or to gain too much political power, in reality, many such friars have evolved into advisors for local leaders--mayors, lords, dukes, and even kings. As they've done so, they've managed to become very wealthy, and their small churches have evolved into massive cathedrals.
While they remain politically impotent as a group, individually, many of them are among the most politically powerful men in the land.
That original quroum of learned individuals was called the Inquisition, and their original purpose was to inquire (hence their name) into matters occult. Terrasa was rocked by a series of occult scandals, including the revelation that the king's own brother was possessed by a daemon, and the putting on of a play, of all things, called "The King in Yellow." This play was maddening; most of the audience that saw its only known performance went violently insane and rioted; killing or consigning to an asylum many of Terrasa's cultural elite and leaving their ranks thinned for generations.
The recommendations of this body to the king were that some occult threats were too dangerous to be allowed to fester, and that the King should take a stronger hand in preventing them before they came to be scandals or crises like the two that rocked the capital that year. And so, in a strange joint venture between these academics, clergymen, and the King's own Guard, the Inquisition was formed, a secret police dedicated to the rooting out of occult and supernatural threats throughout the empire.
Their mandate was, of necessity, somewhat secret, and although the rumors of a militant Inquisition that act as a secret police are not uncommon, few really know much truth about the organization. And the fact of the matter is, that the body is very constrained anywhere except in its strongholds in the capital and a few other large cities of the Empire; beyond that, the only authority that Inquisitors possess is that which they can demand by nature of their strength of will and arms. In fact, in many areas, they openly clash with other bodies of authority, who do not recognize them at all.
In this way, the Inquisition is less politically powerful in DARK•HERITAGE than in some other settings... and yet, they are if anything, perhaps even more sinister. Lacking overt political power, they are the masters of subterfuge and espionage, and consider themselves above any law. And while, of course, many Inquisitors are less kind-hearted than one would like, they serve mankind as a whole, preventing forces which would otherwise overwhelm the fledgeling mortal race from doing so, at least for a time. If a few innocents have to be sacrificed along the way--or even if many innocents have to be sacrificed along the way, the greater good stipulates that such sacrifices are necessary and should not deter them from their task.
And if the Inquisition must utilize the weapons of its enemy to serve the greater good... they do not shy away from that either.