The basis of this growth is partly the story-telling instinct innate in all men, which loves to heighten an effect, sharpen a point or increase a contrast - the instinct which breathes in Icelandic sagas like that of Burnt Njal; partly the instinct of idolization, if it may be so called, which leads to the perversion into impossible greatness of an approved character, and has created, in this instance, the legendary figures of Peter the Hermit and Godfrey of Bouillon (qq.v.); partly the religious impulse, which counted nothing wonderful in a holy war, and imported miraculous elements even into the sober pages of the Gesta.
Von Sybel, in his Geschichte des ersten Kreuzzuges, suggests that in the camp of the pauperes (which existed side by side with that of the knights, and grew increasingly large as the crusade told more and more heavily in its progress on the purses of the crusaders) some idolization of Peter the Hermit had already begun, during the first crusade, parallel to the similar glorification of Godfrey by the Lorrainers.
In this idolization Peter naturally became the instigator of the crusade, just as Godfrey became the founder of the kingdom of Jerusalem and the legislator of the assizes.
The former, composed at Antioch about 1130, contained an idolization of the Hermit: the latter is a poem written about 1180 by Graindor of Douai, who used as his basis the verses of the crusader Richard (see the edition of P. Paris, 1848).