Constantine I AE Follis. Trier mint, 310-313 AD.

Obv: CONSTANTINVS P F AVG, laureate, draped and cuirassed
bust right (but seen from behind, not in RIC)
Rev: MARTI CONSERVATORI, Helmeted and cuirassed bust of 
Mars right, star on helmet earpiece (not in RIC).
No mint mark

RIC 885 var (bust type, star on helmet).

With permission of Roma Numismatics, August, 2009