Antoninianus of Probus

The Antoninianus of Probus is a small late Roman coin struck during the reign of Emperor Probus between 276 and 282 AD. The example shown here displays the defining feature of the denomination: a radiate (spiked-crown) portrait of the emperor on the obverse, the mark that distinguished the antoninianus from the laureate-crowned denarius.

By Probus's day the antoninianus was no longer good silver but a billon or bronze coin with only a thin silver content, often finished with a light silver wash. These pieces were produced in enormous numbers across many imperial mints, which makes Probus one of the most commonly encountered emperors in ancient-coin collecting today.

Probus rose to power in 276 AD during the turbulent late-third-century period often called the Crisis of the Third Century, a stretch of rapid imperial turnover, military pressure on the frontiers, and a badly debased coinage. A capable soldier-emperor, he spent much of his reign campaigning against Germanic and other groups along the Rhine and Danube before being killed by his own troops in 282 AD.

The antoninianus had been introduced early in the third century as a double-denarius but was steadily debased over the following decades until, by Probus's time, it circulated as a bronze or billon coin with only a trace of silver. Probus continued the coinage reforms begun under his predecessor Aurelian, and his radiates were struck at a wide network of mints across the empire.

Because the reverse of this particular coin is not shown, its specific type and legend cannot be read from the image alone. Probus antoniniani are known for an unusually rich variety of reverse designs, including standing deities, personifications such as the emperor on horseback, military and imperial-virtue themes, and elaborate bust styles on the obverse.

Identify this coin first by the radiate crown — a spiked, sun-ray diadem — on the emperor's portrait. That crown is what makes the piece an antoninianus rather than a laureate denarius, and it is clearly visible on the obverse shown here. The surrounding legend on Probus coins typically renders his name and titles in abbreviated Latin, commonly beginning IMP (for Imperator) and including PROBVS AVG.

The coin is small and thin, generally around 20-24 mm in diameter and only a few grams in weight, struck in billon or bronze. Genuine examples are often brown, olive, or grey from age, and some retain patches of the original thin silvering. The metal is not magnetic and should not look like bright modern silver.

The reverse is not visible in this image, so the exact reverse type and its mint mark cannot be confirmed here. On a complete coin, the reverse legend and the small mint mark in the exergue (the flat area below the design) are the keys to pinning down the issuing mint and the specific type.

Antoniniani of Probus are among the most affordable and widely available ancient Roman coins because they were struck in vast quantities and survive in large numbers. Common, worn examples typically trade for modest sums, often in the range of a few dollars to a couple of tens of dollars, making them a popular entry point into ancient coinage.

Value rises with condition, surviving silvering, sharp detail, and desirable reverse types or unusual busts. Well-centered coins with clear legends, attractive patina, or scarce mint marks can command meaningfully higher prices, and exceptional pieces sell for more still. Because the reverse is not shown here, the specific type — a major factor in value — cannot be assessed from this image alone.

As with all ancient coins, price depends heavily on eye appeal and authenticity rather than a fixed catalog figure. Recent sales of comparable Probus radiates in similar grade are the best guide, and examples from a reputable dealer or with a credible provenance carry the most confidence.