It was founded in about 1170 by Walter de Claville, lord of the manor of Burlescombe, for the Augustinian canons regular as the Priory of the Blessed Virgin Mary and Saint John the Evangelist. He appears to have been a descendant of Walter I de Claville (floruit 1086), one of the 52 Devon Domesday Book tenants-in-chief of King William the Conqueror, who had 32 landholdings in Devon. The original Anglo-Saxon name of the site donated by Walter II, perhaps a sub-manor of Burlescombe, was "Leigh" (Domesday Book "Leige"), which after the foundation of the Abbey became known as "Canons' Leigh" and was Latinised by mediaeval scribes to "Leigh Canonicorum" (i.e. "Leigh of the canons"), now "Canonsleigh".