A 141-coin Roman gold hoard sat in Luxembourg soil beside buried wartime munitions

A cache of late Roman gold coins pulled from a field in northern Luxembourg turned into a four-year excavation that had to work around unexploded munitions left over from the Second World War. The results, published in a new numismatic study, point to something researchers did not expect: a sizable share of the gold traces back to a mint in ancient Anatolia, thousands of kilometers away.

How the Holzthum hoard came to light

The discovery began in September 2019, when two amateur fieldwalkers using metal detectors surveyed a site known as Um Rank near the village of Holzthum, in the commune of Parc Hosingen, following guidance from Luxembourg’s National Institute for Archaeological Research, known as INRA. They turned up 38 gold coins and reported the find immediately, which triggered three additional archaeological field campaigns. Those campaigns eventually uncovered the remains of a multi-phase Late Roman fortified structure known as a burgus, along with its surrounding ditch system, sitting beneath the same ground, as Arkeonews reported.

Digging around live wartime explosives

What made the excavation unusual was not the coins themselves but the conditions archaeologists had to work in. The Ardennes region saw heavy fighting during 1944 and 1945, and the site still contained munitions and explosives left behind from that period. INRA teams worked alongside the Luxembourg Army’s Explosive Ordnance Disposal Service, known as SEDAL, to clear the area safely while excavation proceeded between 2020 and 2024. Officials only announced the find publicly after that four-year process concluded, citing both the archaeological significance of the deposit and the danger posed by the leftover ordnance.

Nine emperors, 141 coins, and an Anatolian surprise

By the end of the dig, researchers had recovered 141 late Roman gold solidi, coins minted under nine successive emperors who reigned between 364 and 408 A.D. Numismatists later compared the hoard against similar late Roman gold deposits found in Belgium, the Netherlands and western Germany, and one detail stood out: seventeen of the Holzthum coins were struck between A.D. 364 and 367 at Nicomedia, a major Roman mint on the Sea of Marmara in what is now northwestern Turkey. Those seventeen coins account for more than 12 percent of the regular coins in the hoard, a concentration that the study’s authors say has no close parallel in the Coin Hoards of the Roman Empire database for a hoard from this region.

Gold that may have traveled with an army

Researchers David Wigg-Wolf, David Weis and Lynn Stoffel, who published their analysis in Schweizer Munzblatter, suggest the eastern coins may have moved west with Emperor Valentinian I and his army. Valentinian was proclaimed Augustus at Ancyra, modern-day Ankara, in A.D. 364, before heading first toward Italy and later into Gaul. Other coins in the hoard point to a second wave of movement: pieces struck at Constantinople between A.D. 383 and 388, along with two Honorius solidi produced at Sirmium around A.D. 394-395, may have arrived with troops returning west after Emperor Theodosius I defeated the usurper Eugenius in A.D. 394. Even so, the study stops short of tying the buried hoard to a single dramatic event, noting no specific war or crisis can be securely identified as the reason it was buried and never retrieved. The numismatic evidence places the hoard’s closing date at around A.D. 395 or shortly after.

Not every coin in the hoard is what it appears to be

The analysis also turned up inconsistencies among the coins themselves. Two fragmentary pieces matching the RESTITVTOR REIPVBLICAE type were found to be plated rather than solid gold, with one likely an ancient imitation based on its portrait style. Another coin has an unusually dark surface that may indicate a higher proportion of silver or tin, though the metal composition has not yet been confirmed through formal analysis. A separate solidus has a bent edge exposing what looks like two bonded metal layers, a feature researchers plan to study further to determine how it was made and whether the layers separated through later damage.

What the hoard is worth, and what it reveals

Luxembourg compensated the hoard’s legal rights holders 308,600 euros following an independent numismatic assessment that weighed the coins’ condition and rarity, including several scarce issues bearing the face of the short-lived emperor Eugenius, who ruled the western empire from A.D. 392 to 394 before his defeat by Theodosius I. But researchers say the hoard’s real value lies in what it shows about the late Roman world’s reach: a fortified outpost in rural Luxembourg held gold struck in cities as distant as Trier, Rome, Constantinople, Antioch and Nicomedia, offering physical evidence of how imperial money and armies moved across enormous distances during the empire’s final, turbulent decades.

The Holzthum hoard now ranks among the largest gold coin discoveries ever recorded in Luxembourg, and its scale gives researchers an unusually large sample to work with compared with the smaller, more fragmentary hoards typically found along the empire’s northwestern frontier. Because the coins can be individually dated by emperor and mint, the collection functions less like a single treasure and more like a physical timeline, tracking how gold entered and moved through the region across roughly three decades of Roman rule. That level of resolution is part of why the study’s authors were able to propose specific troop movements, rather than simply describing the hoard as evidence of wealth buried during a vaguely defined period of instability.

This article was created with the assistance of AI and reviewed by an editor.

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