Maximianus Herculeus AE Antoninianus. Siscia mint, AD 289-290. 

IMP C M A VAL MAXIMIANVS PF AVG, radiate, cuirassed bust left.
CONSERVATOR AVGG, Emperor standing right, holding sceptre, facing Hercules, standing left, leaning on club, each holding a patera over a lighted altar.

A in lower right field.
Mintmark dot XXI dot HP dot.

RIC V-II 580.

Contributed by CarpeDiem Numismatics, August, 2021