Hadrian surrendered Trajan's conquests in Mesopotamia, considering them to be indefensible. There was almost a war with Vologases III of Parthia around 121, but the threat was averted when Hadrian succeeded in negotiating a peace.
In 121, the province of Gallia Narbonensis was established after the victory of Quintus Fabius Maximus over a coalition of Arverni and Allobroges in southern Gaul in 123.