Proculus and Bonosus, the respective commanders of Gaul and Germany, revolt in 280, declaring themselves joint emperors, according to the Historia Augusta.

The extent of popular support for the rebels is unclear, though it may have reached as far as Spain.

Probably Proculus has family connection with the Franks, to whom he will turn in vain when his bid for imperial power is failing.

A native of Albingaunum (modern Albenga in Liguria), though he is accounted a noble, his ancestors had been brigands and are the source of his vast wealth.

Proculus is able to arm two thousand slaves of his own latifundia after seizing imperial office in the West.

He is married to a woman named Vituriga, who was given the nickname "Samso" for her capabilities (considered "unwomanly" by the author of Historia Augusta), and at the time of his usurpation, he has one son, Herennianus, aged four.

Proculus is an ambitious soldier, who had commanded more than one legion as tribune; when in 280 he is asked by the people of Lugdunum, who had started a rebellion against Emperor Probus to take the purple, accepts, proclaiming himself joint emperor with Bonosus.

"He was, nevertheless, of some benefit to the Gauls, for he crushed the Alamanni—who then were still called Germans—and not without illustrious glory, though he never fought save in brigand-fashion" (Historia Augusta).