Inquisitors are non-controllable members of The Papal States in Medieval 2: Total War . Inquisitors are often sent in when the percentage of Christians dips to an undesirable level in any given settlement. They can prove to be serious problems due to the fact that they have no quarrel with trying and executing any member of your faction who's piety is in question. They can fortunately be killed by assassins of your faction or any other faction. But this act is risky due to the fact that inquisitors belong to The Papal States, and so if the assassination fails, it will be seen as a hostile against The Papal States.