Watch List notes:

Gallienus. AD 253-268. Antoninianus (20.5mm, 3.14 g, 5h). Viminacium mint. Issue 3c. IMP GALLIENVS P F AVG, radiate, cuirassed(?) bust right, shield on right shoulder, spear pointing forwards and upwards / GERMANICVS MAXIMVS, trophy of arms, with seated captive on either side. MIR 36, 840l1; RIC V (joint reign) 382 var. (bust type; Milan). Near VF, some roughness and deposits. Extremely rare, only one noted in MIR (from the Clamerey hoard).

Bought from CGB, Paris, 2015.

This appears to be the earliest example of a military bust, with spear and shield, on a circulating, non-provincial coin of the Roman Empire. See introductory chapter on portraiture for further discussion.