Constantius I, posthumous issue, AE3, Rome, 317-318 AD.

DIVO CONSTANTIO PIO PRINCIPI, veiled and laureate head right.
REQVIE-S O-PTIMOR MERIT, Constantius seated left, raising right 
hand and holding sceptre. 

Mintmark RP.
RIC VII Rome 105, rated R4

Contributed by Javier Gadney, June 2011.