EQVITI Coins of Probus

sulla80
Jan 15, 2021
5 min read

An antoninianus of Probus with a Salus reverse completes a set of six coins carrying a hidden message. I first learned of this series from Doug Smith's page, EQVITI Coins of Probus. It was a while ago, and I think I used CompuServe to connect to Geocities at the time.

Background: A Cavalry Commander in Revolt

Start with a coin of Postumus struck at Milan by Aureolus. From about 258 CE, under Gallienus, Aureolus had served as magister equitum, master of the horse, commanding a new mobile cavalry force based at Mediolanum. In 268 he turned against Gallienus and declared for the Gallic emperor Postumus, striking coins at Mediolanum in Postumus's name. A cavalryman celebrating the cavalry is a natural fit: VIRTVS EQVIT saluting the virtue, bravery and military strength of the cavalry.

Aureolus, Romano-Gallic usurper, 267-268 CE. Antoninianus, Mediolanum (Milan) mint, 3rd officina, struck in the name of Postumus, 3rd emission, mid-268 CE. 2.19g.

Obv: IMP POSTVMVS AVG, radiate, draped, and cuirassed bust of Postumus right.

Rev: VIRTVS EQVIT, Virtus advancing right, holding transverse spear and shield; [T] in exergue.

Ref: RIC V Postumus 388

From Aureolus to Probus

The revolt ended badly for everyone. Gallienus besieged Aureolus in Milan and was assassinated there in 268, with his own senior officers implicated. Claudius II took the throne, Aureolus surrendered and was killed soon after, and the cavalry command that had made Aureolus dangerous passed on.

The succession then ran fast. Claudius II died of plague in 270. His brother Quintillus held power briefly before support shifted to Aurelian. Aurelian was murdered by his own officers in Thrace in 275 while marching east against the Sasanians. Tacitus followed and died in 276, Florianus lasted a few months, and Probus emerged as emperor of a reunified empire in 276.

The Coded Series

Probus came from Sirmium in Pannonia and rose through the army. The equites, often translated as knights, were the propertied order ranking below the senators at Rome. The authors of Roman Imperial Coinage connect Probus to the mounted arm directly:

"It is not unlikely that Probus, whose warlike operations extended over a great area, may also have owed much to the mounted arm, and desired to express that indebtedness. That he himself was no mean commander of the horse may be indicated by the title Equitius Probus, applied to him in the Epitome."

The Epitome passage they mean is this one:

"After him, Tacitus took power, a man of singular character, who died at Tarsus from a fever in the two hundredth day of his reign. Florian succeeded him. But when the majority of the troops chose Equitius Probus, a man experienced in military affairs, Florian, on the sixtieth day of his reign, as if exhausted in the contest for power, when he had cut open his veins, was consumed by loss of blood."
-Epitome de Caesaribus, 36

The coins themselves work like this. Across the six officinae of a mint, the mintmarks carry the letters of a single word in sequence, so that a complete set of six spells the word out. Rome spells AEQVITI. Ticinum spells AEQVIT in one series and EQVITI in two others. Four series in all are known, struck between about 280 and 282 CE.

The Nineteenth-Century Debate

The pattern was first published by Anton Missong in 1873. He read the code as a marker of standardization, arriving alongside a visible tightening of die quality, with the letters of AEQVITAS distributed among six workshops as a sign of their equality. He noted the contrast with earlier emissions: the reverses of the coded coins are uniform, and the obverses run to a fixed pattern, the bust radiate and cuirassed facing right in one emission, facing left with imperial cloak or in a radiate helmet in another.

"Both in Tarraco and in Rome there was a lot of variability in the manufacture of the mint dies. During the third consulate in Tarraco, greater regularity in obverse and reverse appears to have been introduced, and at the same time, as a sign of equality (AEQVITAS) in the six offices, each of them took one of the first six letters of AEQVITATI as a symbol."

Missong rejected the reading of AEQVITI as money designated for the cavalry, on the ground that Probus would hardly have issued coin for the knights alone, and he dismissed the idea that the code was a mint official's name, since the same code appears at both Rome and Ticinum. His mint attribution has since been corrected: the coins he assigned to Tarraco are now given to Ticinum.

Theodor Mommsen, writing in 1887, took the opposite view on that last point:

"It seems evident to me that this is the name of the official who directed the coinage under Probus, Equitius or Aequitius, both spellings are found, but the first predominates. It is not an uncommon cognomen in the third and fourth centuries, and this Equitius may be an ancestor of the consul of the same name in 374 CE."

Where Things Stand

Both nineteenth-century explanations have been set aside. Karl Pink's 1949 study, still the standard treatment of Probus's coinage, reads Equitius as a signum, an informal additional name, belonging to Probus himself, which is what the Epitome preserves. Others read the dative AEQVITI as an appeal to or on behalf of the horsemen.

No answer is settled. The code may carry no more meaning than a convenient set of six letters for mint control. A further clue may lie in the rare Siscian antoniniani of Probus with a horse's head on the obverse, published by Margetić and Margetić. For a full discussion of the competing readings, see Gert Boersema's page, and PROBVS.net for a listing of the relevant coins.

The Set

Here is my set, drawn from a mix of emissions and officinae, ordered by officina (P primus, S secundus, T tertius, Q quartus, V quintus, VI sextus) so that the coded letters spell EQVITI. For more on the reverses and workshops, see Chip Scoppa on Forum Ancient Coins. There are three emissions from Ticinium and another one from Rome. The third series from Ticinium includes a star which you see on 4/6 of my coins.