Summary: coin, Antoninianus of Postumus. O: Radiate bust R, [IMP POST]VMVS AVG; R: Mars advancing R holding shield and spear. T in exergue, VIRTVS [EQV]IT
Identification note: In AD 260 Postumus, who was governor of Lower Germany, rebelled. He took control of Germany, Gaul, Spain and Britain, which became known as the Gallic Empire. He died at the hands of his own soldiers in 268 when he refused them permission to sack Mainz.
Identification note: layer 4