Battle of Gaugamela
Arrian lists Orontes and a certain Mithraustes as two commanders of Armenian forces in the Battle of Gaugamela in 331 BC. The interpretation of this passage is controversial, with different historians interpreting it as indicating that Mithraustes commanded the infantry, or that there were two different contingents of Armenian cavalry in this battle, or even that Armenia was divided into two parts ruled by two satraps.