Constantine I, AE follis, London.

CONSTANTINVS PF AVG, helmeted, laureate cuirassed bust left,
holding spear forwards and shield on arm.
MARTI CO-NSERVATORI, Mars standing right, helmeted and
in military dress, holding vertical spear, point 
downwards and resting left hand on shield.
Star in left field.
Mintmark PLN

RIC VI London 257.

Contributed by gb29400 of the Forum Ancient Coins, Feb, 2013