Armenia had been divided during the reign of Shapur III according to the terms of a peace treaty. But this arrangement barely survived the reign of Shapur III. By about 390, Khosrov III, the King of Armenia under Persian suzerainty grew wary of his subordination to Persia and entered into a treaty with the Roman Emperor Theodosius I who deposed Arshak III and made him the king of a united Armenia in return for his allegiance. Enraged Bahram IV took Khosrov prisoner and confined him to the Castle of Oblivion and made his brother Vram-Shapuh upon the Armenian throne. Khosrov had appealed to Theodosius for help but the latter refused to intervene as it would constitute a breach of the peace of 384.
Bahramn IV is often regarded as a harsh man who entirely neglected his duties. His conduct, it is recorded, grew so unbearable that he was ultimately assassinated by his own troops who surrounded him and shot him with arrows.