First Gallic Civil War (Gaul Rising)

Background
Shortly after the de facto secession of the Gallic Empire from the Roman Empire, Gallic Emperor Postumus set up a new Senate in Colonia Agrippina. At first, the Gallic Senate was identical to its Roman counterpart. During the 270s, Postumus began to believe that in order to maintain political stability, it was necessary for him and his successors to deal with the Senate as an equal, rather than make it a puppet. In accordance with this view, Postumus gave the Senate the power to depose and replace the emperor, choose the emperor's successor in the event of the emperor dying or abdicating without choosing his own successor, and the power to appoint the majority of the provincial governors.

The second Gallic Emperor, Victorinus, did not share Postumus' vision of genuine cooperation between the emperor and the Senate. Throughout his rule, he frequently removed senators who opposed his agenda from the Senate and replaced them with loyal allies of his. The first and most notable time he stuffed the Senate with his partisans was in 282, when the Senate was about to vote on a motion to depose him.