Augustus, son of Valentinian I., succeeded to a share of the Western Empire on the death of his father in A.D. 375. After a reign of eight years he was murdered by the partizans of a rebel aspirant to the imperial throne. Though only twenty-four at the time of his death, he had given proof of possessing many excellent qualities. He was just and gentle, zealous for the public good, and a true friend of Christianity.

a Benedictine of the twelfth century, is said to have been born at Chiusi in Tuscany, and to have resided at Bologna. His name has been preserved by his collection of the canons or decrets of the church, published at Mainz in 1472, under the title of Decretum Gratiani. This work was a great improvement upon its predecessors; but from the want of standard authorities and a sound principle of criticism many of the canons in it are quite apocryphal, and the text in many places very corrupt. Gratian, however, was himself well aware of the defects of his work, and warns his readers not to put too much faith either in his statements or his conclusions. He is often guilty of the most absurd self-contradictions in his endeavor to reconcile incongruous canons; and is accused by the Abbé Fleury of unwittingly extending the authority of the Pope, by his doctrine that the Pope was not himself subject to the canons. As Gratian's errors were leading to awkward results, an edition of his Decretals was published in 1582 by order of Gregory XIII.; in which the more flagrant mistakes were corrected. A treatise, De Emendatione Gratiani, by Antonius Augustinus, is an indispensable supplement to Gratian's own work.