Arnulf Seamundson was a Norse merchant who traveled to Alexandria during the 9th century. There, he was introduced into a blood cult dedicated to the ancient god Set and finally granted the Embrace by a member of the Followers of Set. When Arnulf returned to Oslo, now known under the epitheh Jormungandrsson, he founded the Hall of Jormungandr as a doomsday cult who worshipped Jormungandr, the World-Serpent, which Arnulf declared to be another facet of Apep, the serpent Set had worshipped during his active times. Despite the fact that the influence of the Hall never became widespread, he gained a foothold into jewelry trade and fostered a small Setite colony far away from Egypt, that was able to pass themselves as vampires from other clans.
Arnulf eventually became primogen of Oslo, due the fact that many kindred mistaked him and his brood for Toreador. He lost this position after World War II because he supported the Germans too eagerly, but was named Keeper of Elysium instead.