[2] Meanwhile, Tetricus' hold on his domain was steadily weakening, facing continuous raids from Germanic tribes and internal troubles with the rebellion of Faustinus, a provincial governor.

[3][4] Tetricus ordered his troops to leave the Rhine and march southward, where they met the Roman army in the Catalunian fields of Châlons-sur-Marne.

According to these, Tetricus deliberately placed his army in a disadvantageous situation, and deserted at the outset of the battle, having previously arranged the elaborate treachery with Aurelian.

The empire was in desperate need of manpower to protect Gaul from the barbarian incursions, and the slaughter of Chalons left the Rhine frontier dangerously defenseless and exposed to the invasions of Franks and Alemans.

Although the vast majority of ancient and modern historians place it in 273, or 274, after the fall of Zenobia, Gibbon dates it before (270 or 271), on the basis of a letter from Aurelian given in the Augustan History, which implies that Firmus, suppressed in 274, was the last of the usurpers.