The Vanir - heavily shocked by Gullveig´s reports - could not believe that there was a tribe able to treat an inculpable woman in such a brutal and malicious way.
After long consultation they commanly agreed to march with their hosts on Valhalla in order to avenge the torture of the beautiful, fair woman.
As Odin becomes aware of the Vanir with the giantess Gullveig at the fore he commanded the Æsir to arms.