 Walafrid Strabo (ninth century), a Benedictine, was credited with the "Glossa Ordinaria" on the entire Bible.It is a brief explanation of the literal and mystical sense, based on Rabanus Maurus and other Latin writers, and was one of the most popular works during the Middle Ages, being as well known as "The Sentences" of Peter Lombard.Anselm of Laon, professor at Paris (twelfth century), wrote the "Glossa Interlinearis", so called because the explanation was inserted between the lines of the Vulgate.