About Yervanduni ( old Eruanduni , Greek Orontid ) origins.
It is frequent that a piece of information detached from his real context can create more confusion than understanding. One such information is the inscription from Pergamon city about the supposedly Bactrian origin of Orontes satrap who ruled Armenia in 4th century BC. The one who is also mentioned by Xenophon in Anabasis.
Elcibekyan presents and discuss this inscription. Here some important things.
+ The inscription describes an event when Orontes deported Pergamon city people to another location close to sea coast/gulf.
+ This deportation occured when Orontes rebelled against the Persian king. It was during the famous Great Satraps rebellion around 362BC. The exact reason of this rebellion is not known but it seems Orontes was unhappy when the Persian king wanted to remove him from Armenia to Western Anatolia as a satrap. So he organized a rebellion in Western Anatolia after which the Persian king has no choice than to return him back to Armenia.
This same Orontes son of Artasura is also mentioned in Nemrut inscriptions. He is the number 6 in the second picture. From Nemrut inscription we learn once more that his father was the Artasura. But we also learn that he had a grandfather also named Aruandes/Orontes.
This number 4 Aruandes/Orontes might have ruled Armenia before 450BC and neither Graeco-Roman sources neither Armenian sources have no information about him. Nevertheless it is quite obvious that Xenophon's era Orontes (number 6) was not a newly arrived person in Armenia. At last his grandfather also ruled Armenia. And it is quite unlikely that he came to Armenia from Bactria then moved to Western Anatolia to organize a rebellion there for getting back to Armenia. That doesn't make much sense.
So why do this confusing term Bactria is there in the inscription?
Well Elcibekyan gives a plausible explanation. In ancient times Bactria was also known as Zariaspa. A similar name existed in ancient southern Armenia. Mountain and a range Zarasp close to those places from were Orontid dinasty possibly originated ( mount Siah Kuh near modern Turkish-Iranian border). It's quite possible that Pergamon people simply confused the Zarasp in Armenia with Zariaspa in Bactria. And erroneously assumed that Orontes came from Bactria.