At its heart are the heroic deeds of Sigurd the dragon slayer who acquires magical knowledge from one of Odin's Valkyries. Yet it is also set in a very human world, incorporating strands from the oral narratives of the fourth and fifth centuries, when Attila the Hun and other warriors fought on the northern frontiers of the Roman Empire. One of the great books of world literature, the saga is an unforgettable tale of princely jealousy, unrequited love, greed and vengeance. With its cursed treasure of the Rhine, sword reforged and magic ring of power, it was a major influence for writers including William Morris and J. R. R. Tolkien and for Wagner's Ring cycle.