The "Historia Augusta" says that Claudius was a military tribune () in the army of the emperor Decius. After that, the "Historia Augusta" says that Claudius was leader of a Roman legion () in the time of the emperor Valerian. Next, the "Historia Augusta" says that Claudius was governor of all Illyricum () when Gallienus was emperor. The Latin historian Aurelius Victor and the Greek historian Zonaras wrote that Claudius was a tribune () at Ticinum (Pavia, Italy) in 268.