The Illuster Sacellum (Sanctuary's Lot Supplement)
From D&D Wiki
Illuster Sacellum
Venerating the dream god Rune to the exclusion of all other powers, this well-established faith is lead by extended families of sovereigns of dawn.
Illuster Sacellum doctrine demands direct confrontation with anything the church considers unclean: strangers from the dark, corrupted creatures, anyone who colludes with The Dark itself, non-illuster magicians, and in some cases, all other non-illuster churches. Consequently, the Illuster Sacellum frequently finds itself in a near-perpetual state of war and has been snarled in conflicts (both political and theological) since its founding in the 7th century (a.s.).
The Illuster Cantorum, the so-called Purifiers, represent the militant wing of the church. Its crusader lead armies are the merciless firey sword of the Illuster Sacellum.