Constantine. AE3. Ostia. 312-313 AD. 

IMP C CONSTANTINVS PF AVG, laureate, cuirassed bust right / 

SOLI INV-I-CTO COMITI, Sol standing left, holding globe 
close to body and raising right hand. 

Mintmark MOSTP. 

RIC VI Ostia 83. 

Courtesy of Roma Numismatics, Feb, 2010