The Ides of March, March 15th, was, more or less, just a day on the ancient Roman calendarβa festival day, admittedly, and, like 12 other Ides on the Julian calendar, one against which earlier or later days were themselves defined. Today, by that reckoning, is not the 13th of March; it is two days before the Ides.
But this Ides is forever conflated with one of its occurrences, in the year 44 BC, when 60-odd Roman senators led by Brutus and his brother-in-law Cassius assassinated Julius Caesar in the Senate House of Pompey. Caesar had been declared βDictator Perpetuoβ in the Senate only weeks before, and this splinter group had deemed a permanent head of state to be a threat to Rome as a republic. A commemorative denarius, the standard silver coin used as legal tender in Rome, was minted by an exultant Brutus in 43 BC, and a specimen of this coin now resides here in New Haven, part of the numismatics collection at the Yale University Art Gallery.

I was ushered into the numismatics study room in a sunny corner of the gallery by curator Benjamin Hellings. The Ides of March coin was already waiting on a tray. I inspected it with a magnifying glass while Hellings pointed out the details. Embossed on the obverseβor headβof the coin was Brutus in profile, looking sorrowful and surprisingly youthful beneath unruly curls. Turning it over, I could see the symbols of the senatorial conspiracyβtwo military daggers, or pugio, flanking a helmet-like cap called a pileus. βThe pileus [in ancient Rome] was part of the process of manumitting slavesβor freeing slaves,β Hellings explained. βSo the coin is reading, βHeβs killed Caesar and heβs given freedom to people.β Freeing them from slavery ofβthe tyranny ofβJulius Caesar.β βEID MAR,β a Latin abbreviation meaning βon the Ides of March,β is embossed underneath.
The coin looked old enough to have survived the event. I speculated that, because the two daggers had different hilt designs, they perhaps depicted the actual daggers used by Brutus and Cassius, though some details were lost to wear. The embossed images rubbed low, and the clouds of green oxidation on both sides of the coin, suggested the passing of eons.
But, alas, the coin is a fake, minted sometime in 1980 AD.
βI think, if I recall correctly, it was a counterfeit from central or eastern Europe,β Hellings explained. βItβs a very good counterfeit. But for those of us in this world, itβs now easily recognized as a fake.β The coin in fact received its βimitationβ designation from the YUAG shortly after it arrived in 2001. βItβs one of those things where numismatists who handle thousands and thousands and thousands of these develop a connoisseurship, and youβre able to spot [a forgery]ββthrough deviations in the features of Brutusβs face, perhaps, or in the shape of the letters surrounding him. Mostly, Hellings added, βitβs just based on the dies.β
Dies in ancient coin-making (and in modern coin-faking) are heavy metal cylinders engraved with the coin image. Struck by hammer, they emboss the image on a metal blank, transforming the blank into a coin. If the blank is placed between two dies, and one die is struck, the blank is embossed on both sides. If the dies in use had been official dies, struck by a magistrate-appointed moneyer, then the coin was official currency. In 1989, a numismatist named Herbert A. Cahn surveyed all the circulating Ides of March coins believed to be authentic (of which there were then 58) and concluded, based on subtle but consistent differences in the images on them, that 26 obverse dies and 8 reverse dies had been used by Brutusβs moneyer. (Because the obverse diesβthe ones that were struck directly by the hammerβwore out more quickly, they were replaced more frequently.) After Cahn, an observant numismatist could pick out the use of a later, forger-made die by the slightly unrecognizable variation of Brutus it left on the forger-made coin.
Also, Hellings said, referring to the level of discernment in an expert inspection, βthe fabric or the materiality of the metal looks a little bit different and off.β For comparison, Hellings then handed me an authenticated Roman coin from 44 BC, the year before the purported vintage of the fake. To my untrained eye, the metal looked the same, but I was nevertheless assured of now holding what was once the pocket change of an ancient Roman. More pointedly, this real coin, bearing Caesarβs profile along with the legend βdict[ator] perpetvo,β is as crucial to understanding the Ides of March as the Ides of March coin that followed it; Caesarβs decision to venerate himself this way was purportedly the last straw for Brutus and his co-conspirators. Together the two coins constitute their explanation for the act.



The Yale Art Gallery has about 2000 denarii in its collection. By comparison, Hellings said, there are now about 100 Ides of March denariiβunearthed and authenticatedβin the entire world. In 2020, an Ides of March coinβstruck in gold, its portrait of Brutus looking as lined and pensive as Lincolnβsβbroke a record for ancient coins by selling at auction for $4,188,393. It was purported to have come from the collection of Baron Gustave von Bonstetten, antiquarian and chamberlain to Emperor Ferdinand I of Austria, but its provenance was later found to have been falsified. Historical association with royalty adds luster to a rare coin. Another gold Ides of March coin was donated to the British Museum by George IV, but was later determined to have been forged.
Only one other gold Ides of March coin has ever gone to market, and Hellings suggested that perhaps all three of them are fakes. (One of them had first appeared in the early 17th century, a little too conveniently soon after the staging of Shakespeareβs The Tragedy of Julius Caesar.) Forgeries are legion, according to Helling. βAny collection that doesnβt have fakes identified just hasnβt been inspected,β he said.
For museum curators, they are teaching opportunities. Budding numismatists learn to authenticate coins by spotting the giveaways in inauthentic ones, like scratches in the silver that reveal a base of copper. So-called plated coins can also be unmasked by their weight, or by the distinctive plink they make against a hard surface. Some plated Ides of March coins are as old as the authentic ones, leading some scholars to speculate that Brutus himself had some minted that way.
Further complicating the Ides of March coinβs history with forgery is the outlaw nature of its original minting. After the assassination, Brutus and Cassius were condemned in absentia, banished in a ruling presided over by one of the new consuls, Octavian (Caesarβs 19-year-old son). Brutus, in exile from Rome but in control of various Roman provinces to the east, had the coin minted from appropriated gold and silver so he could pay the soldiers who marched with him. He and Cassius then lost their respective battles against a Roman army commanded by Mark Antony. The Ides of March coin was recalled by Octavian and melted down, and surely it was the message on them that was really intended for the furnace. But not all renderings of the daggers and cap made it there, setting the stage for forgeries such as the one that, for all its inauthenticity, tells truths about ancient Rome from contemporary New Haven.
Written by David Zukowski. Image 1, featuring the obverse (left) and reverse (right) of the Ides of March coin, comprised of photos by the Yale University Art Gallery. Image 2, featuring the Bela Lyon Pratt Study Room viewed from the YUAGβs Ancient Art room, photographed by Dan Mims. Image 3, featuring one of the denarii commemorating Julius Caesarβs ascension in the YUAGβs Bela Lyon Pratt Gallery, photographed by Dan Mims. Images 4 and 5, featuring progressively wider views of the Pratt Gallery, photographed by Dan Mims.