Diocletian  284 - 305  A.D.

Coin Description Diocletian, AE 20mm a silvered antoninianus (indicated by the radiate crown), The coin is well centered but also well worn and the silvering on the coin is completely gone. VM 49, RBC 11
Obverse The portrait is of Diocletian a radiate (the spiked crown) and draped bust facing right. The legend reads IMP C C VAL DIOCLETIANVS PF AVG meaning: IMP (Imperator = the Emperor / supreme military commander) C (Caesar) C VAL DIOCLETIANVS (his name Caius Valerius Diocletianus) PF (Pius Felix / Dutiful and Wise) AVG Augustus which defines him as the emperor.
Reverse

The reverse shows the emperor standing right holding a short scepter, he's receiving a Victoriola from Jupiter standing left with a chlamys over his left shoulder and holding a long scepter. The legend reads CONCORDIA MILITVM which translates as "Unity of the army". The letters HB appear between the two figures this is probably the mintmark.

Mint The exergue has no visible letters but the HB between the two figures could stand for Heraclea second officina (Beta).
The Entire Story The entire story of this coin would read: Our supreme commander Caesar Caius Valerius Diocletianus the Dutiful and Wise Augustus who brings unity to our army. The unity of the army ofcourse brings victory as seen by the victoriola handed to Diocletian by his "father" Jupiter.