Antoninianus of Aurelian

The Antoninianus of Aurelian is a base-silver (billon) Roman coin, and the example shown carries the radiate-crowned head of Emperor Aurelian on the obverse with a standing deity or personification on the reverse. The radiate crown, a ring of pointed rays, is the defining mark of the antoninianus and distinguishes it from the laurel-wreathed denarius.

Struck during Aurelian's short but pivotal reign of 270-275 AD, these coins are among the most commonly encountered pieces of the later third century. Aurelian reformed and improved the debased antoninianus late in his reign, and his radiates, often still bearing traces of their original silvery surface, are a popular and affordable entry point into collecting Roman imperial coinage.

Aurelian ruled from 270 to 275 AD during the depths of the Roman "Crisis of the Third Century," a period of civil war, invasion, and monetary breakdown. He earned the title Restitutor Orbis ("restorer of the world") by reuniting a fractured empire, defeating the breakaway Palmyrene realm of Zenobia in the east and the Gallic Empire in the west, and fortifying Rome with the Aurelian Walls.

By his accession the antoninianus, a double-denarius introduced by Caracalla in 215 AD, had collapsed into a small coin of mostly bronze with only a thin silver wash. In about 274 AD Aurelian reformed the coinage, issuing a heavier, better-silvered antoninianus often marked in the reverse field or exergue with the numerals XXI (or the Greek KA), generally understood to signal a controlled ratio of twenty parts base metal to one of silver. His coins were produced at numerous imperial mints across the empire, including Rome, Milan, Siscia, Serdica, Cyzicus, Antioch, and Tripolis.

Look for a small, dark coin roughly 20-23 mm across and about 3-4 grams, struck in billon (silvered bronze) rather than good silver. The obverse shows a male bust facing right wearing a spiked radiate crown, encircled by a Latin legend naming the emperor in forms such as IMP AVRELIANVS AVG or IMP C L DOM AVRELIANVS AVG. The surface may retain patches of the original silvering or appear brown-to-green from bronze corrosion.

The reverse typically depicts a standing deity or personification with an accompanying legend, common types include SOL INVICTVS (Sol raising a hand), CONCORDIA MILITVM, ORIENS AVG, VIRTVS MILITVM, and RESTITVTOR ORBIS. Post-reform pieces frequently show the mark XXI or KA plus mint and workshop letters in the exergue below the figure. Because each die was cut by hand, minor variation in style, legend spacing, and centering between genuine coins is normal.

Aurelian's antoniniani were struck in very large numbers and survive in quantity, so most circulated examples are among the more affordable ancient Roman coins. Value is driven chiefly by preservation of detail, how much original silvering remains, strike quality, centering, and the desirability of the reverse type and mint.

Well-centered coins with sharp portraits and substantial intact silvering command clear premiums over worn, corroded, or off-center pieces, and scarcer reverse types or mints can add further value. Coins tied to notable themes (such as Sol Invictus) or with attractive surfaces are the most sought after. Fakes and modern reproductions exist, so authentication matters at higher values; treat any single figure as approximate and check recent specialist sales.