Armenia had been constantly the source of war between the Roman and Sasanian Empires. In 378/9, Shapur II had achieved Iranian hegemony over the country after its regent
Manuel Mamikonian submitted to him. A force 10,000 of Iranian soldiers led by general
Surena were dispatched to Armenia. Surena was given the title of
marzban (
margrave), which indicates that Armenia was now a Sasanian province. Under Ardashir II, however, Manuel rebelled and succeeded in maintaining independence against both the Iranians and Romans in the early 380s. However, just before his death in 385/386, he seemingly placed Armenia under Roman protection. With his death, many Armenian
nakharars (grandees) revolted against the
Arsacid king
Arshak III () and appealed to Shapur III for another king. Shapur III responded by crowning
Khosrov IV as king, and gave him his sister
Zurvandukht in marriage. He then sent an invasion force into Armenia, which occupied most of the country. Arshak III was forced to withdraw to the western region of
Acilisene, where he awaited Roman reinforcements. Instead of declaring war, Iran and Rome agreed to come to terms through diplomacy. An
agreement was made to partition Armenia. The boundary stretched through
Theodosiopolis in the north and
Amida in the south, which meant that most of Armenia remained in Sasanian
hands, including the two Arsacid capitals of
Artaxata and
Dvin. With this treaty, the Romans also fully acknowledged Iranian hegemony over all of
Iberia. When this treaty exactly took place is unsure; most scholars believe the treaty was made in 387, whilst a few others state 384 or even in 389 or 390. Both sides were to cooperate in the defense of the
Caucasus, with the Romans agreeing to pay the Iranians roughly 500 lbs (226 kg) of gold at irregular intervals. While the Romans saw this payment as political allocations, the Iranians saw it as tribute. In order to further reduce the political and economic power of Iranian Armenia, Shapur III deprived the country of several of its provinces;
Artsakh,
Utik, Shakashen,
Gardman and Kolt were given to
Caucasian Albania (ruled by a
collateral line of the Arsacids);
Gugark (ruled by the
Mihranids) became subject to Iberia; and
Arzanene (ruled by a
bidaxsh, i.e. margrave),
Paytakaran, Korjayk (
Corduene) and
Parskahayk were incorporated into Iran. Arshak III soon died, which made the Romans abolish their branch of the Arsacid monarchy and create the province of
Western Armenia. As a result many of the
nakharars who had followed him subsequently rejoined the Iranians. The Arsacid monarchy in Iranian Armenia continued to last for a few decades, until its abolishment by king
Bahram V () in 428. Shapur III's religious tolerance towards the Christians is reported by the historians
Elishe and
John of Ephesus. According to the former, Shapur III granted the Armenians lavish gifts and exempted their Church from royal taxation. Besides the dispute over Armenia, Shapur III seems to have clashed with the
Alchon Huns to the east; coinage indicates that the Alchon Huns seized
Kabul from him sometime before 388. They duplicated the same coin mints issued by Shapur III, with the only difference being the newly added
Bactrian inscription "αλχοννο" (
alxanno), added to display their takeover of Sasanian territory. The loss of the city was a major blow, as it had been a center of coin manufacture since the 360s. Shapur III died in 388, after reigning for five years. He died when some nobles cut the ropes of a large tent that he had erected in one of his palace courts, so that the tent fell on top of him. He was succeeded by his son
Bahram IV. Another of his sons,
Yazdegerd I, later succeeded Bahram IV in 399. == Coinage ==