Constantine II, AE3. Trier. 317 AD. 

FL CL CONSTANTINVS IVN N C, bare head right, draped & cuirassed, seen from the back.
PRINCIPI IVVENTVTIS, Constantine II, laureate, in military dress, standing 
right, cloak spread and hanging down behind both shoulders, holding globe 
and transverse spear. 
F-T across fields. 
Mintmark BTR. 

RIC VII Trier 172. Extremely rare (R4).

With permission of Roma Numismatics, Jul, 2010