The Abbey of Saint-Denis is a Benedictine monastery in Saint-Denis.
The abbey was founded in 630 for Benedictine monks by Dagobert I, and soon became one of the most important of its kind in France. French Kings tended to pray at the abbey before leaving for battle, as well as several queens and princesses also spending part of their lives there. The abbots would serve as advisors to the monarchy, the most famous being Suger, who discovered a First Civilization temple underneath the Basilica of Saint-Denis.
During the French Revolution, anti-royalist revolutionaries desecrated the royal tombs in Saint-Denis, though one of the local monks, Dom Poirier, kept a list of the artifacts that were stolen. The monks were eventually thrown out of the abbey, which was then taken over by mercenaries under the command of Captain Philippe Rose.
Rose worked for Napoleon Bonaparte to find an artifact in the temple under the basilica. The mercenaries procured the list and the relics mentioned in it, keeping them at the abbey and reportedly selling some of them. In August 1794, the exiled Assassin Arno Dorian infiltrated the abbey library to recover Dom Poirier's list.