A pseudonym applied since Erasmus to a commentary on the Pauline epistles which appeared in Rome about 375, falsely attributed to Ambrose* of Milan. The pseudo- Augustinian Quaestiones Veteris et Novi Testamenti are also attributed (e.g., by J.N.D. Kelly) to this author. His identity is not yet established. Augustine attributes part of the commentary on Romans 5:12 to “sanctus Hilarius,” possibly the Christian praefectus urbi at Rome in 383. Ambrosiaster relates Pauline teaching to contemporary legal institutions (Heggelbacher). Like Ambrose and Jerome, he believed the Cross to have broken the hold which the devil gained on men at the Fall, and the eucharistic elements he saw as “types” of Christ's body and blood. His eschatology included a Millennium. Original guilt he did not hold, but his understanding of universal sin in Adam quasi in massa, based on the Old Latin mistranslation of Romans 5:12, did lead on to the Augustinian doctrine.