The third century has been a time of crisis for the Legio III Augusta, which has been stationed at Lambaesis in Numidia for more than two centuries, since the reign of Hadrian, guarding the province from the Berber tribes.

First, it had suffered heavy losses in a war against a desert tribe, having to receive reinforcements from the recently disbanded Legio III Gallica.

The legion had suppressed the revolt of Gordian I and Gordian II in 238, the Year of the Six Emperors,  but had been disbanded by their successor Gordian III.

Valerian reconstitutes the Legio III Augusta in 252 with troops coming from Raetia and Noricum, and gives it the cognomen Iterum Pia Iterum Vindex (Again faithful, again avenger).

The purpose of this reconstitution is to wage a war against a federation of Berber tribes that threaten the empire.