Obviously, the sword was owned by a “Highlander”-style immortal from 12th century Germany, who had to flee his homeland after rising from the dead and being labeled a vampire by the townsfolk. He fled to Sweden, where he was trained by another immortal, and then wandered the world before the Kurgan tracked him down in Siberia and lopped his head off to acquire his power.
Well how else could they start the Democrat Party?