Constantine I, AE follis, 23mm, Trier, 310 AD. 

IMP CONSTANTINVS PF AVG, laureate, cuirassed bust right.
MARTI CONSERVATORI, helmeted, cuirassed bust of Mars right.
Mintmark PTR.

RIC VI Trier 878 var (mintmark).
Unpublished, R5

not in RIC, Gerin (Trier) or Cohen.

Contributed by Dr. Hubert Lanz, auction November 2000, 
Added July 2011.