Marc-Guillaume Alexis Vadier

Marc-Guillaume Alexis Vadier (17 July 1736 – 14 December 1828) was a major French politician of the French Revolution. He is sometimes called the "Great Inquisitor", for his active participation in the Reign of Terror.

He is primarily known for having created the département of Ariège and mostly for having firmly led the Committee of General Security, thus being one of the key figures of the Reign of Terror and the "dean of its political police." Vadier also had an influential role on 9 Thermidor, during the fall of Robespierre, with whom he had a long-standing rivalry.

He managed to avoid reprisals for his role during the Terror, which targeted him following Robespierre's fall, and survived the Revolution, participating in relative anonymity during the First Empire period. He was later exiled under the law targeting regicides during Louis XVIII's reign.

Like Robespierre, Barère, or Billaud-Varenne, his exact role during the Terror is still debated by historians. However, it is acknowledged that a significant part of the repressive measures of the Terror and the executions can be attributed to the Committee of General Security, which he led, and that he participated in organizing the Great Terror by increasing the number of executions alongside Fouché, notably to accuse Robespierre.