Postumus founded the breakaway Gallic Empire in 260 AD after capturing and likely executing Saloninus, son of Gallienus, at Cologne. He held the Rhine frontier more effectively than Rome itself managed during those years, repelling multiple Germanic incursions that the central empire was too stretched to address. His reign of nearly a decade was exceptional stability by the standards of the third-century crisis — ended not by Rome but by mutiny within his own ranks in 269, when he refused to allow his troops to sack Mainz after suppressing a rival's rebellion.
Postumus founded the breakaway Gallic Empire in 260 AD after capturing and likely executing Saloninus, son of Gallienus, at Cologne. He held the Rhine frontier more effectively than Rome itself managed during those years, repelling multiple Germanic incursions that the central empire was too stretched to address. His reign of nearly a decade was exceptional stability by the standards of the third-century crisis — ended not by Rome but by mutiny within his own ranks in 269, when he refused to allow his troops to sack Mainz after suppressing a rival's rebellion.
This 268 issue falls in his final year.