Diocletian. AE Follis. Trier. 298-299 AD. 

IMP DIOCLETIANVS PF AVG, laureate, draped, cuirassed bust right, 
seen from back
GENIO POPV-LI ROMANI, Genius standing left, modius on head, 
naked except for chlamys draped over upper chest and over 
left shoulder, holding patera and cornucopiae

A-star across fields
mintmark TR. 

RIC VI Trier 279a var (unlisted bust type for this series). Scarce.

With permission of Roma Numismatics, Oktober, 2009