(V. of Vaillant), the son of Para or Bab.
According to Vaillant, he was the nephew of Para, being the son of one Arsaces (IV. of Vaillant), who was the brother of Para; this opinion has been adopted by distinguished historians, but it seems untenable. Arsaces IV. reigned a short time together with his brother Valarsces or Wagharshag, who died soon.
In a war against an usurper, Waraztad, the son of Anob, who was the brother of Arsaces III., Arsaces IV. showed such a want of character and energy that he owed his success merely to the bad condnet of the usurper, who was at first supported by the emperor Theodosius the Great.
The weakness of Arsaces being manifest, Theodosius and Sapor III. formed and carried into execution the plan of dividing Armenia. Arsaces was allowed to reign as a vassal king of Constantinople in the western and smaller part of Armenia, while the larger and eastern part became the share of Sapor, who gave it to Chosroes or Khosrew, a noble belonging to the house of the Arsacidae, of which there were still some branches living in Persia.
According to St. Martin this happened in 387. Procopius mentions one Tigranes, brother of Arsaces, who reigned over eastern Armenia, which he ceded to Sapor.
The whole history of the division of Armenia is very obscure, and the chief sources, Procopius and Moses Chorenensis are in manifest contradiction. Arsaces IV. died in 389, and his dominions were conferred by the emperor upon his general, Casavon, who was descended from the family of the Gamsaragans, which was a branch of the Arsacidae.
It seems that this general was a most able diplomatist, and that his nomination was a plot concerted between him and Theodosius to bring all Armenia under the imperial authority ; Casavon declared himself a vassal of Chosroes, and this vassal suddenly broke his allegiance towards Sapor, and submitted to Theodosius. On this Bahrain IV., the successor of Sapor, invaded Armenia, seized Chosroes and put Bahram Shapur (Sapor) the brother of Chosroes, on the vassal throne of (eastern) Armenia. (392.) In 414, Chosroes was re-established by Yezdegerd I., the successor of Bahram IV., and after the death of Chosroes, in 415, Yezdegerd's son, Shapur or Sapor, became king. Sapor died in 419, and till 422 there was an interregnum in Armenia till Ardashes (Artasires) ascended the throne. (Procopius, de Aedif. Justin.
3.1. 5; De Bell. Pers.
2.3; Moses Choren. 3.40, &c., 49, &c.)