In the World of Darkness, the Inquisition is an organization within the Roman Catholic Church tasked to rid the world of evil and heresy in all its forms in the name of God. Part of the Inquisition is the Society of Leopold. The Society specifically pursue and fight supernaturals, as they believe that all supernaturals are part of the army of the Antichrist. They are a major threat to every group of supernaturals because of their extensive knowledge, training, equipment, preparation and fanatical zeal.
The roots of the Society of Leopold go back to the Roman days, but the official formation of the group goes back to 1231, when Leopold von Murnau, a German Dominican, was granted special dispensation by Pope Gregory IX. to combat supernatural evil. The following centuries saw quite a few ups and downs, until in 1908 Pius X reorganized the Society, and gave them the freedom to act more independently from the Catholic Church.