The sources for the Life of Blessed Giles may be divided roughly into two main classes. There are the accounts of him and references to him in manuscripts dealing with other subjects: and there are the manuscripts containing more or less complete and connected versions of his Life. It will be simplest to deal first with the former class, and to do so in the generally accepted order of date of composition.

[1230.] I. The Legenda Prima or First Life of St. Francis, written by Thomas of Celano at the direction of Pope Gregory IX, at some date between the Saint's canonisation in 1228 and 25 May, 1230, contains the earliest account of the conversion of Giles and of his joining himself to St. Francis. It is only a matter of a few lines and the reference is I Cel. x. 25.

Hunc vero, post non multum temporis, sequitur frater Ægidius, vir simplex et rectus ac timens Deum, qui longo tempore durans sancte, iuste ac pie vivendo, perfectae obedientiae, laboris quoque manuum, vitae solitariae, sanctaeque contemplationis nobis exempla reliquit.

One further brief reference to him occurs in I Cel. xii. 30, where, speaking of the missionary journey undertaken by St. Francis and his seven companions, he mentions how B. Giles and Bernard made their way to the shrine of Saint James at Compostella:–

Tunc frater Bernardus cum fratre Ægidio versus Sanctum Iacobum iter arripuit.