Arsacid dynasty of Armenia
In 112, Trajan was provoked by the decision of Osroes I to put his own nephew Axidares on the throne of the Kingdom of Armenia. The Arsacid dynasty of Armenia was a branch of the Parthian royal family established in 54. Since then, the two great empires had shared hegemony of Armenia. The encroachment on the traditional Roman sphere of influence by Osroes ended the peace which had lasted for some 50 years.