Battle of Bagavan

In 369 CE, Shapur II, Shah of the Sassanid Empire, persuaded the Armenian King, Papas (Pap) to change his allegiance. Under Shapur's influence Papas murdered Cylaces and Artabanes and sent their heads to Shapur as a sign of loyalty. The Roman Emperor, Valens, sent one of his generals, Arintheus, with an army into Armenia and Pap immediately reverted to his loyalty to Rome.

In the winter 370, Shapur decided to settle the Armenian matter by force; he declared the Treaty of 363 (a thirty year peace agreement between the Persians and the Romans) to be void and began amassing an army to invade Armenia during the next spring.

Learning of the impending attack, Papas mustered an army at Barevand. The Romans, under the command of Valens' generals Traianus and Vadomarius, had armies at Erhand and Baxish. They also marched for Bagrevand and build a fortified camp while they waited for the Armenians to assemble. Eventually, the Armenians fielded an army of 90,000 men. It was decided that the Sparapet (general) Mushegh I Mamikonian would command the Armenian forces while the Romans remained under their own command.

The combined Armenian-Roman army met the Sasanid force near a village called Dzirav (near Bagrevand) and were victorious. The Armenians broke the Sasanid battle lines and caused a route. Faustus of Byzantium gives considerable credit for the victory to sparapet Mushegh I Mamikonian. Movses Khorenatsi of Armenia and Roman historian Ammianus Marcellinus noted that Valens' generals did not actively participate in the battle, but rather were engaged in protecting the king. During the ensuing battles more Armenian territories were reclaimed from the Sasanids, including Arzanene and Corduene which were ceded to Shapur II by Jovian in 363.

Although he lost the battle, Shapur was determined not to give in. He launched several minor invasions and raiding parties into Armenian territory, before another major assault led to a second battle at Gandzak.[3] At the Battle of Gandzak the Roman-Armenian army defeated the Sasanids for the second time that year. After the battle Shapur sent envoys and a truce was agreed upon. The truce would last for seven years.[4]