With the ShB promotional site up, we finally know something about Hrothgar. They hail from Illsabard and are the origin of Gunbreakers, a practice descended from Queen Gunnhildr's royal guard. One tribe, the Helions(named by scholars, not themselves) are chiefly loyal to the crown, and the other tribe, the Lost, are nomadic. There was initially hostility when they crossed into Aldenard because they didn't know the common tongue, but disappeared quickly once they learned it.