 The valkyrs "ride" to war, decide the issues of fighting, and conduct the fallen to heaven; their riding is like that of heroes and gods".Various theories have been proposed about the origins and development of the valkyries from Germanic paganism to later Norse mythology.Rudolf Simek suggests valkyries were probably originally viewed as "demons of the dead to whom warriors slain on the battlefield belonged", and that a shift in interpretation of the valkyries may have occurred "when the concept of Valhalla changed from a battlefield to a warrior's paradise".