Vattier de Rideaux, Viscount of Eiddon, was the head of military intelligence for Emperor Emhyr var Emreis. His lover was Carthia van Canten. The intelligence chief was one of the organizers of the attack by the Scoia'tael on the mages' conference on Thanedd Island. Because the attack did not achieve its primary objective, de Rideaux and the emperor came to the conclusion that there were traitors among them, namely: Vilgefortz, Rience, Cahir, and possibly Isengrim Faoiltiarna.