GRATIANUS AUGUSTUS (A.D. (Roman Emperor A.D. 367-383). Eldest son of Valentinian. I., by his first wife, Severn. He was born at Sirmium, in Pannonia. While he was still nobilissimus puer, or heir apparent. he was created consul, and in 367 was elevated by his father to the rank of Augustus (joint Emperor) at Ambianum (Amiens). in Gaul. In the following year he accompanied his father in his expedition against the Alemanni, in order that he might be accustomed to warfare. On the death of Valentinian. Gratianus became senior ruler of the Western Empire, taking as a colleague his half-brother Valentinian II. Gaul, Spain, and Britain fell to Gratianus's share; and as his brother was only four years old he was practi cally the sole ruler in the West, fixing his resi dence at Treviri (now Treves). while the East continued to be ruled by his uncle, Valens. Dur ing the first part of his reign a fierce warfare was carried on against the tribes who possessed the Danubian Provinces and Illyricum; and he was on the point of marching into Thrace, to assist Valens against the Goths, when he was suddenly called upon to defend his dominions against the T.entienses, a tribe of the Alemanni. After the invaders had been defeated Gratianits advanced toward the Eastern Empire, hut while on the way he learned that his uncle Valens had been de feated and killed by the Goths near Adrianople (August 9, 378). The sovereignty of the Eastern
Empire then devolved upon Gratianu5, but, feel ing his inadequacy to the task of ruling the whole Empire, he recalled Theodosius (q.v.) from Spain, and appointed him his colleague on Janu ary 19, 379. Gratianus possessed some admirable virtues, but his character was yielding and pli ant, and he was often led to the commission of acts of cruelty. and tyranny. His persecution of the pagans, and afterwards of heretic Christians, alienated the affections of his subjects generally, while his fondness for frivolous amusements and unworthy associates excited the contempt of the army, so that when Maximus was proclaimed Emperor by the legions in Britain, crowds of the disaffected flocked to his standard. Gratianus was defeated by him near Paris, and afterwards fled to Lugdunum (Lyons), where he was over taken and killed by Andragathius, whom Maxi mus had sent in pursuit of him, on August 25, 383. For the reign of Gratianus, see Gibbon's Decline and Fall of the Roman Empire, ed. Bury, chs. 25-27.