Constantine I AE Follis. London mint, AD 312-313.

CONSTANTINVS AVG, helmeted, cuirassed bust left, holding
spear and shield.
MARTI CON-SERVATORI, Mars standing right, helmeted and
in military dress, cloak spread over upper chest, 
holding upright spear, point downwards, left hand on 
shield.
Star in left field.
Mintmark PLN.

RIC VI London 260.
Rare.

Sold by Bertolami Fine Arts ACR Auctions - Auction 9, Lot 816, April 2014.