There isn't one (Going back to the original post). Thats what makes this a far superior campaign setting. The lowe magic and the decreased influence of individuals as opposed to nations. Much more cohesive and realistic. Anyway I remember reading somewhere (one of the gods and dietys suplements it included something about a priest trying to brign a god back to life by sacrificing artifacts to him in the 2nd edition) that Birthright was sealed of because of Desimar so you really cant go plane hopping like that. Although uit was kinda foggy cause some expansions and anventures there seem to be several planar beings and then there is always Adriala to screw things up even more.