Constantine the Great AE Follis. 307-310 AD. 

Obv: IMP CONSTANTINVS P F AVG, laureate cuirassed bust right 
Rev: MARTI PATRI PROPVG, Mars advancing right, nude except for helm & chlamis, 
  carrying transverse spear & shield, PLN in ex.

RIC Vol VI #108 of London, rated Scarce.

Contributed by Steve Santore, March 2007.