Diocletian, RIC 329 Treveir 284-305 CE.

Obverse: IMP C C VAL DIOCLETIANVS PF AVG, Radiate, draped & cuirassed bust right.
Reverse: IOVI CONSERVATOR-I AVGG, TR. Jupiter & Diocletian face to face. Diocletian is standing to the left, turned right, dressed in militrary, holding a scepter in left hand. Jupiter is naked standing at right, turned left, the coat on the shoulder, holding a long Scepter, the left hand and a globe nikephoros in the right hand, giving to the emperor.
Mintmark XXI, Treveir, 23.2 mm., 4.0 g.

Comments: The workshop of Tripolis is rare. Opened at the time of the reform of 274 Aurelian's reign, will close under the diarchy in 290. Antioch, as the nearby workshop of Tripolis, seems to serve as military dispensary supplying the army funds in order to pay the troops in the field.
History: Diocletian, born in 245 in Dalmatia (Split), is an Illyrian Emperor. It is purple after eliminating Aper, praetorian prefect and father-in-law and assassin of Numerien, November 20 284. Fighting first against Carin, youngest son of Carus, he was defeated at the Margus the following year; but Carin is murdered and Diocletian remains only August. He appointed Maximian, a compatriot, Caesar in November 285, then auguste April 1 286. It just created a new political regime, the diarchy where two emperors share political and military power, but Maximian remains subordinate to Diocletian. Diocletian ranks under the Jovian (Jupiter) protection while Maximian was Herculean gasoline (of Hercules). Diocletian spent the first ten years of his reign to make war in the East, while Maximian remains in the West. Diocletian was the first emperor of Bas Empire, in the words of Gibbons, and the originator of the dominate.