The coin sold to an anonymous phone bidder for $1.9m (£1.54m) at a Classical Numismatic Group auction.
Equivalent to 10 gold aurei, the Diocletian (284-305AD) denio weighing just under 54gms ranks among the largest denomination Imperial Roman gold coins known.
Struck at a newly opened mint in the north Italian city of Aquileia in 294AD, this coin represented vast wealth at the time of issue and must have been created for a special occasion. It is assumed to have been made to mark Diocletian’s 10th year in office – a significant achievement at a tumultuous period in Roman history.
The design is considered a masterpiece of late classical portraiture. A muscular and unadorned profile of the emperor appears to the obverse with the seated figure of his patron god Jupiter holding a thunderbolt and a sceptre on the reverse. The legend Iovi Conservatori reads as Jupiter the Protector.
While several 10 aurei medallions of Diocletian are recorded, this is the only example from the Aquileia mint and the only denio to be offered for sale at public auction in a century. The last, found as part of the Beaurains Treasure in Arras, were sold soon after discovery in 1922.
The sale of this example (officially graded ‘choice’) took place at the Intercontinental Barclay Hotel in Manhattan as part of the 51st NYINC where coin dealers and collectors gather from all over the world. The estimate had been set at $500,000.
The winning bid of $1.9m on January 11 (with 22.5% buyer’s premium the final price was $2.33m) is the highest price paid for a Roman Imperial coin, beating the Hadrianic bronze sestertius c.135-36AD sold at SFr2m ($1.65m) by Numismatica Genevensis in 2008.
Roma Numismatics set a new record for any Roman or classical coin when a Brutus Eid Mar-type gold aureus, struck shortly after the murder of Julius Caesar, took £2.7m in London in October 2020. The coins (only three are known in gold) are thought to have been made by a military mint travelling with Brutus during the late summer or autumn of 42BC, to pay his troops.
Theft from event
Separately, a dealer had some of his coins stolen from his booth at the NYINC event (which ran from January 6-15) while he was away from his stand. According to reports the stolen coins were valued at $100,000.