Constantine I, AE Follis. 307-308 AD. Trier. 

Obv: IMP CONSTANTINVS PF AVG, laureate, cuirassed bust right
Rev: PRINCIPI IVVENTVTIS, Constantine standing right, in 
military dress, holding transverse spear and  globe, S-A 
across fields, PTR in ex. 

RIC VI Trier, 785, rated scarce.

With permission of Roma Numismatics, July, 2009