Diocletian (284-305 A.D.) -  Pre-Reform AE Antoninianus - 20.23mm, 3.33gr
Obverse
IMP C C VAL DIOCLETIANVS PF AVG
Diocletian, his radiate, draped and cuirassed bust right
Reverse
CONCORDIA MILITVM, XXI in Exergue, B in field.
Diocletian receiving Victory on globe from Jupiter.

Minted at officina B in Antioch (Antakya, Turkey) between 293 and 295 A.D.
Reference: 
Webb, P.H., "Roman Imperial Coinage", Volume 5, Part 2 (RIC), p256, nr. 322c
Sear, D.R., "Roman Coins and their Values" (RCV 4th Revised Edition), p303, nr. 3510
Cohen, H, "Descriptions Historique des Monnaies frappees sous l'Empire Romain" (C), nr. 34
Van Meter, D., "Handbook of Roman Imperial Coins", p276, nr. 21.
Suarez, R., "Encyclopedia of Roman Imperial Coins" (ERIC), p393, nr. 57 (B29, O26, R015, T031, M02)
Quality: Fair