Armenia ceased likewise to be a Roman province, and returned to its former position as a Roman vassal-state and a Parthian appanage of the second son.[54] The princes of the Albani, and the Iberians on the Caucasus, and the numerous small dynasts in the south-eastern corner of the Black Sea likewise remained dependent.[55] Roman garrisons were stationed not merely on the coast in Apsarus[56] and on the Phasis, but, as can be shown, under Commodus in Armenia itself, not far from Artaxata; in a military point of view all these states belonged to the district of the commandant of Cappadocia.[57] This supremacy, however, very indefinite in its nature, seems to have been dealt with generally, and in particular by Hadrian,[58] in such a way that it appeared more as a right of protection than as subjection proper, and at least the more powerful of these princes did, and left undone, in the main what pleased them. The common interest--which we have formerly brought out--in warding off the wild trans-Caucasian tribes became still more definitely prominent in this epoch, and evidently served as a bond in particular between Romans and Parthians. Towards the end of the reign of Hadrian the Alani, in agreement apparently with the king of Iberia, at that time Pharasmanes II., on whom it primarily devolved to bar the pass of the Caucasus against them, invaded the southern regions, and pillaged not only the territory of the Albanians and Armenians, but also the Parthian province of Media and the Roman province of Cappadocia, though matters did not come to a waging of war in common, but the gold of the ruler then reigning in Parthia, Vologasus III., and the mobilising of the Cappadocian army on the part of the Romans,[59] induced the barbarians to return, yet their interests coincided, and the complaint which the Parthians lodged in Rome as to Pharasmanes of Iberia, shows the concert of the two great powers.[60] [Sidenote: Parthian war under Marcus and Verus.]