Vologases III, whose eastern domains were untouched, took advantage of the weakened state of Osroes I to regain lost territory, and finally defeated him in 129.

Vologases III had to face an invasion by the nomadic Alans from 134 to 136, while in the east, he sought to increase the political and military actions as a response to the enlargement of the Kushan Empire.

Vologases III, however, did not protest, either due to not being powerful enough, or possibly because he did not want to put the thriving long-distance trade in jeopardy, from which the Parthian state was gaining hefty income from.

[2][5] This gave the Roman emperor Trajan (r. 98–117) a pretext to invade the Parthian domain and take advantage of the ongoing civil war between Vologases III and Osroes I.

[7][9] However, these gains were short-lived; revolts occurred in all the conquered territories, with the Babylonians and Jews pushing the Romans out of Mesopotamia, and the Armenians causing trouble under the leadership of a certain Sanatruk.

[11] The weakened state of the western part of the Parthian Empire gave Vologases III—whose eastern domains were untouched—the opportunity to regain lost territory seized by Osroes I.

[13][12] Vologases III also faced new challenges in other places; in 134, the king of Iberia, Pharasmanes II (r. 117–138) caused the nomadic Alans to invade the domains of the Parthians and Romans.

[1] Vologases III, however, did not protest, either due to not being powerful enough, or possibly because he did not want to put the thriving long-distance trade in jeopardy, from which the Parthian state was gaining hefty income.

A lone Buddhist source records that the Kushan ruler Kanishka I defeated a Parthian invasion during the time of Vologases III.