wandering scholar from the Île-de-France, author of the first vernacular life of St. Thomas Becket, which reveals passionate devotion to the saint and shows considerable literary merit.

Guernes wrote his Vie de saint Thomas Becket (composed in verse c. 1174) from Latin sources; in order to check some conflicting facts, he visited Canterbury, where, it was said, he would often read his work to the companies of pilgrims visiting the martyr's tomb.