The Temple of Order, originally. In WoW he's gone missing. Some say he's the general of the faceless, General Vezax. They think he's been corrupted by Yogg.
In Eastern Plaguelands there's a place named after him, Tyr's Hand. Scarlet Crusade controls that place. But how would they have heard of him if he never left Storm Peaks and was turned into a faceless one?
I think he wasn't. I think he left Storm Peaks, because something was wrong. He then wandered around Azeroth to find help, probably even taking human shape. He met Scarlet Crusade who named their city after him.