The pilgrimage puzzles historians and Kelly comments that "it is extraordinary that an early medieval king could consider his position safe enough to abandon his kingdom in a time of extreme crisis". She suggests that Æthelwulf may have been motivated by a personal religious impulse. Ryan sees it as an attempt to placate the divine wrath displayed by Viking attacks, whereas Nelson thinks he aimed to enhance his prestige in dealing with the demands of his adult sons. In Kirby's view: