"A very old Andrastian institution. One that goes back to before the founding of the Chantry itself, almost a thousand years ago."
A quick history lesson: the Tevinter Imperium controls the continent, the First Blight happens (brief digression for what darkspawn are- corrupted monsters from underground following the will of a blighted dragon), the Imperium has its control shaken, an alliance of the southern Alamarri tribes creates a contending nation. Led by a divinely-inspired princess (that's Andraste), they ally with the oppressed elves and push the Tevinters back to north of the Waking Sea. Andraste is betrayed, taken prisoner, and executed by the Imperium. Her cult (and belief in the Maker she proselytized for) lives on, however, and the Imperium never regains control of the south. It's a chaotic and lawless time as people rediscover what they want to be without the shadow of empire pressing down on them. The original Inquisition was a group of zealous cultists who had it as their mission to protect the common people from the ravages of the disorder, righting wrongs and striking down tyrants. Not all the records paint them in an entirely complimentary light. 'Inquisition' is a name that will command fear as well as respect.