The Numismatic Bibliomania Society


The E-Sylum: Volume 25, Number 49, December 4, 2022, Article 24


Here's the press release for CNG's Triton XXVI auction coming up in January, highlighting the Diocletian denio. -Editor

  Diocletian denio obverse Diocletian denio reverse
Largest Roman Gold Coin Offered in 100+ Years Tops Triton XXVI Auction

The largest Roman gold coin offered at auction in more than a century, a unique 10- aureus gold medallion of the Emperor Diocletian, tops the ancient and world coin offerings in Classical Numismatic Group LLC's Triton XXVI auction slated for January 10-11 in conjunction with the New York International Numismatic Convention.

The huge gold piece, termed a denio by specialists, is nearly 40mm in diameter and weighs 53.65 grams, larger in diameter and nearly twice the weight of a U.S. double eagle. It is believed to have been struck in AD 294 to mark Diocletian's tenth anniversary of rule, according to Paul Hill, Senior Numismatist for CNG's London office. It will be offered as Lot 830 in Triton XXVI, with an estimate of $500,000.

The Diocletian denio has been graded by Numismatic Guaranty Corporation with an extraordinary Choice AU?, Strike: 5/5, Surface 5/5, Fine Style. It is easily the largest Roman gold piece ever certified by NGC, said David Vagi, NGC's Director of Ancient Coins. "NGC Ancients is pleased to have handled this exciting piece, which stands out as one of the finest Roman medallions in existence," Vagi added.

The coin is not only spectacular for its remarkable size and weight, it is also a superb miniature work of art in its own right, Hill said. When you take into account the historical significance of this medallion, struck at a key point in the conflict between paganism and Christianity, you have one of the most important Roman coins ever to be offered at auction.

CNG is very gratified the collector who owns this amazing piece chose to consign with us, said Michael Gasvoda, Managing Director. This coin is joined by many more outstanding and historically important pieces in our twenty-sixth Triton auction in New York, which will be one of the most important and memorable auctions in CNG's nearly five-decades in operation.

Diocletian, who reigned AD 284 - 305, is famous as the emperor who restored order to the Roman Empire after decades of anarchy, and as the ruler who launched the Great Persecution, a last-ditch effort to exterminate Christianity. The 10-aureus medallion, struck at the midway point of his two-decade rule, was created as a special handout to an important military officer or politician as a reward for loyalty and service. The subtext of a coin representing ‘ten gold aurei for a decade of rule' would have been obvious to the receiver, Hill noted.

The medallion depicts a bare head of Diocletian on the obverse, with close-cropped hair and beard in the military style of the third century AD soldier emperors, with the legend IMP C G VAL DIOCLETIANVS AVG (Imperator [Emperor] Caesar Gaius Valerius Diocletianus Augustus). The reverse depicts the god Jupiter seated left on a throne, holding a thunderbolt in his right hand and a scepter in his left, with an eagle at his feet, clutching a laurel wreath in its beak. The legend reads IOVI CONSERVATORI – Jupiter the Protector. The letters A Q beneath the throne indicate the coin was struck at the mint of Aquileia, an ancient city on the north-eastern coast of Italy.

Jupiter, the king of the Roman pantheon of deities, was chosen by Diocletian as his personal guardian, Hill said. He had restored order to the Roman world in part by sharing his rule with three other men, Maximian, Galerius and Constantius, an arrangement called the Tetrarchy. But Diocletian remained the senior emperor that the other three deferred to, just as all other Roman deities all bowed to Jupiter.

I find the portrait of Diocletian on this medallion to be almost mesmerizing in its power, Gasvoda added. The engraver of the dies used to strike this piece was a supremely talented artist, able to convey the man's forceful personality with a marvelous economy of line.

Only a handful of other ten-aurei medallions are known to exist, all of them in museums or institutional collections. All known gold denios date to the period of the Tetrarchy. As far as we have been able to determine, this is the only medallion of this size and weight sold in the past 100 years, Hill said.

Sessions One through Four of Triton XXVI, comprising 1,316 lots of Ancient, World, and British coinage with a total estimate of $7.5 million, will be held live at the InterContinental Barclay Hotel in New York City on January 10 and 11, 2023, and webcast live on CNG's website,

To receive a printed copy of the full-color catalog of Triton XXVI, or to inquire about consigning to future Classical Numismatic Group auctions, write to, or call (717) 390-9194.

For more information, see:

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Wayne Homren, Editor

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