Europe 387: Peace of Acilisene
Magnus Maximus’ overthrow of Gratian (383) was reluctantly recognized by the eastern Roman emperor Theodosius, who faced too many threats in the East to deal with the usurper. An uneasy peace between the emperors lasted until 387, when Theodosius stabilized the eastern frontier by agreeing to partition Armenia with the Persians.
384? Cession of Manuel Mamikonian▲
In c. 384 Manuel Mamikonian, the effective ruler of Armenia, placed the Armenian king Arshak III and his kingdom under Roman protection. However, when Mamikonian died the following year, the Armenian nobility rose into revolt and drove Arshak into Acilisene province, in the far western part of the country. The nobles then called on Sasanian Persia for support, encouraging Shah Shapur III to enter eastern Armenia with his army and appoint Khosrov IV as the new king.
384 Magnus Maximus’ return to Britain▲
After securing his rule over Gaul, Magnus Maximus briefly returned to Britain to support his allies against the Picts and Scots. During this campaign, he restored some degree of Roman rule in the north of the island, possibly with the aid of Saxon mercenaries, and, according to tradition, established the line of Galloway (Novantae).
384 Recognition of Magnus Maximus▲
After overthrowing Gratian in 383, Magnus Maximus sent embassies to Theodosius I in Constantinople and Valentinian II in Mediolanum (Milan), asking for recognition and that the 12-year-old Valentinian come to Treverorum Augusta (Trier) to live under Maximus’ protection. When Valentinian and his mother Justina refused—and instead made use of the delay to fortify the Alpine passes against an invasion of Italy—Maximus appointed his own son Flavius Victor as Caesar. However, Theodosius, who was not yet ready for war in the West, agreed to recognize the usurper and for several years the three Augusti co-existed uneasily.
385? Gildo and Magnus Maximus▲
In 385 or 386 Valentinian II appointed the Berber prince Gildo as Comes Africae. Gildo had probably known both Theodosius I and Magnus Maximus from the Roman campaign against his brother Firmus in 372–375, so his appointment may have been a compromise between the emperors. Although it appears that Maximus had some influence in Africa in this period, Gildo would ultimately side with Theodosius when war broke out in 387.
By the mid-380s a faction of Greuthungi Goths had overpowered some tribes north of the Danube and began demanding that the Romans allow them to cross the river into Illyricum. Hurrying to the scene, Promotus, the magister peditum of Thraciae, extended his forces along the river bank and deployed Gothic-speaking agents to trick the Greuthungi leader Odotheus into launching a crossing on a given night. Prepared for the invasion, the Romans sunk many Gothic boats as they attempted to land, then moved on to seize large numbers of the enemy, including women and children. Informed of the victory, Theodosius soon arrived and either conscripted the captives into his army or resettled them in Phrygia.
386?–387 Magnus Maximus enters Italy▲
In c. 386 Valentinian II, now based in Aquileia, sent his second-in-command Domninus to Augusta Treverorum (Trier) to strengthen relations with Magnus Maximus. After hosting Domninus with great honor, Maximus sent him home with a contingent of his own troops, ostensibly to help defend the Pannonians against barbarian raiders. However, once these troops had been led across the Alps, they took control of the mountain passes, allowing Maximus and his entire army to enter Italy unopposed in early 387.
387 Peace of Acilisene▲
In c. 384, shortly after the accession of Shah Shapur III, Rome and Persia began negotiations over Armenia—a cause of tension ever since its acknowledgement as an independent Persian vassal in 363. By a treaty concluded in 387, Shapur and the Roman emperor Theodosius I agreed to divide the country between them, with the Romans accepting the western fifth and the Persians taking the rest. At the same time, Theodosius recognized Persian influence over the Kingdom of Iberia and agreed to a payment of gold at irregular intervals. The treaty marked the beginning of over a century of relative peace between the two powers, interrupted only by two brief wars (in 421–2 and 440).