 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 " . Simek says that this original concept was " superseded by the shield girls — Irish female warriors who lived on like the einherjar in Valhall . " Simek says that the valkyries were closely associated with Odin , and that this connection existed in an earlier role as " demons of death " . Simek states that due to the shift of concept , the valkyries became popular figures in heroic poetry , and during this transition were stripped of their " demonic characteristics and became more human , and therefore become capable of falling in love with mortals [ ... ] . " Simek says that the majority of the names of the valkyries point to a warlike function , that most of valkyrie names do not appear to be very old , and that the names " mostly come from poetic creativity rather than from real folk @-@ belief . " 
