Antoninianus - Postumus FIDES MILITVM

Postumus seized power in 260 AD by having Saloninus — Gallienus's teenage son and co-emperor — executed at Cologne, then declared himself emperor of a breakaway realm covering Gaul, Britain, and Spain. The FIDES MILITVM type was no accident of design: it was a direct political statement to the Rhine legions whose loyalty had just made his coup possible, and whose continued support was the only thing keeping Gallienus's retaliatory campaigns at bay. Postumus held him off for nearly a decade.