Diocletian; AV Aureus (before the monetary reform); Siscia; 286-287.
Obv. Laureate, helmeted, draped and cuirassed bust of Diocletian to the left, a large shield on the left arm, holding a spear pointed upwards in the right hand, captured "three-quarters" from behind. IMP C DIOC[LETIA]NVS P F AVG.
Rv. Naked Jupiter stands to the left with a cloak over his shoulders, holding a long sceptre in his left hand and a thunderbolt in his right hand. IOVI CONSER - VATORI around, no mintmark in the exergue.
Gold, 5.34 g, 20 mm (26 mm with the attached loop), 5h. RIC V.2 p. 245 no. 247; Calico 4497; Depeyrot 1/4.
Grade: F, at 12 o'clock on the obverse, there is an attached sturdy loop adorned with granulation.
The prototype for this depiction is the aurei of Probus from the Siscia mint, with the obverse legend IMP C M AVR PROBVS AVG, paired with the reverse where the emperor, wearing a toga and holding a scepter, drives a free-standing quadriga P M TRI P COS III. They are also extremely rare; neither RIC nor Calico records them. Only 3-4 specimens of such aurei with identical dies are known - NAC 25, 25.6.2003, lot 567 = NAC 52, 7.10.2009, lot 572; Helios 3, 29.4.2009, lot 231 = NAC 102, 24.10.2017, lot 559 = Roma 20, 29.10.2020, lot 666 = NAC 131, 30.5.2022, lot 113; Leu 13, 27.5.2023, lot 346.
In total, there are probably only six aurei of Probus and Diocletian with a heroic portrait like the one presented here in the world.