Archaeologists in France have uncovered five rare iron shackles at a 2,300-year-old Celtic site in Allonnes, indicating the presence of slavery in the Late Iron Age. These shackles, including wrist and ankle restraints, suggest the settlement was a hub for slave trading and was associated with hierarchical social structures. The site also revealed metal tools, religious offerings, and coins, providing new insights into Celtic society and the lives of enslaved individuals, especially women and children, within the context of pre-Roman Gaul.
A pair of the 2,300-year-old Celtic iron shackles discovered at the Allonnes site in France. (© Emmanuelle Collado/Inrap)
Iron Shackles Unearthed at Allonnes
According to an INRAP announcement, five pairs of extremely rare iron shackles have been uncovered at a 2,300-year-old Celtic site in Allonnes, France. The shackles were discovered in 2019 during excavations that began in December 2018 ahead of a housing development.
The finds include a double-wrist restraint, an ankle restraint, and three additional metal restraint portions. The wrist restraint's small 6 cm diameter suggests it may have been used on a woman or child. The ankle restraint weighed over 1 kg (2.2 lbs), revealing the heavy physical burden imposed on enslaved people.
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Left; Wrist shackles with a diameter of less than 6 cm suggests that they were used on women or children. Right; The ankle shackles. Their weight per foot and per ring was greater than 1 kg. (© Elven Le Goff/Inrap)
The artifacts are so fragile they were taken to the Arc'Antique conservation lab in Nantes for chemical treatment and micro-abrasion cleaning.
Thierry Lejars, a specialist in Celtic metalwork is quoted by Live Science, stating that:
"The identification of restraints and weapons suggests a hierarchical social organization composed of dominant and subordinate groups — prisoners or slaves."
The report on the artifacts was presented at the 2026 European Archaeology Days via a public exhibition in Allonnes and included over 90 artifacts that were recovered from the site.
A collection of Gallic coins recovered at the Allonnes location, some of which have been deliberately mutilated. (© Emmanuelle Collado/Inrap)
Allonnes: A Thriving Celtic Hub at the Crossroads of Ancient Gaul
The wider finds at Allonnes have offered a rich insight into Celtic life at the site. The Allonnes settlement was founded in the 3rd century BC at the junction of major trade routes in France's Loire Valley. The site covered approximately 20 hectares and hosted specialist artisan workshops for blacksmiths, coppersmiths, bronze workers, and sheet-metal workers. Small four-post structures housed individual workshops or shops, with nearby open spaces served as markets and fairs, trading local goods and imported Roman wine.
Excavators recovered high-quality metal objects including swords, spearheads, keys, and horse harness fittings. Further evidence of metalworking activity at the location includes raw material bars, semi-finished objects, slag, and metalworking waste from multiple craft traditions.
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Spearheads and arrowheads found during the excavation. (© Emmanuelle Collado/Inrap)
Sacred Offerings and Mutilated Coins
The archaeologists also uncovered a religious sanctuary containing clothing, jewelry, rings and amulets as offerings dedicated to the regional deity Mars Mullo. The sanctuary was in use for nearly 800 years, from the 3rd century BC through the 4th century AD.
According to the report, hundreds of Gallic and Gallo-Roman coins spanning more than five centuries were recovered from the sanctuary. Remarkably, about one-third of the coins had been deliberately mutilated — filed, sheared, or etched with a chisel — stripping them of their commercial value.
Isabelle Bollard-Raineau, ancient-coin expert from the French Ministry of Culture explains the practice:
"These mutilations reveal a ritual intention: the removal of the coin's commercial function in order to dedicate the object to the sacred, thereby ensuring the permanence of the offering."
Along with the coins, swords, scabbards, and spearheads were also found among the ritual deposits, suggesting warrior dedications. Copper-alloy harness fittings, keys, brooches, and rings were also deposited.
The researchers explain how the rituals at the sanctuary were tiered, with some ceremonies restricted to priests such as druids, and others open to the general population in the nearby public spaces.
Assortment of Gallo-Roman offerings discovered at Allonnes, France. (© Emmanuelle Collado/Inrap)
Chains Across Celtic Europe
Although archaeological evidence is far from plentiful, there are indications of widespread practice of slavery in the Celtic Iron Age culture. A 6.6 kg iron gang chain with five neck shackles (100 BC–50 AD) found at Llyn Cerrig Bach, Wales, is one of the comparable Iron Age slave restraints in Europe. A 2014 INRAP excavation in Saintes uncovered at least five individuals in a Gallo-Roman necropolis still wearing riveted iron shackles on wrists, necks, or legs. The Bigbury Camp gang chain found in Kent in England revealed each neck collar could only be released after the previous one was undone, making escape nearly impossible, explained Maidstone Museum.
Evidence such as these lead some scholars to argue Celtic slavery was a significant economic institution in its own right, not merely a byproduct of tribal warfare. Celtic tribes enslaved prisoners of war, convicts, and debtors; enslaved men, women, and children lost all rights and could be bought and sold. As an indicator of how prevalent slavery was in the Celtic culture, in ancient Ireland, the cumal — a female slave — served as a standard unit of currency and legal value.
The trade distances were far reaching, with Roman geographer Strabo documenting an active slave trade between Celtic Britain and the Roman world in the late Iron Age.
Celtic Slavery Exposed
The discovery at Allonnes fundamentally alters our understanding of Iron Age Celtic society in Gaul. Far from being a marginal practice, the presence of these heavy iron shackles (particularly those sized for women or children) indicates that slavery was a deeply entrenched component of the Celtic economy and social hierarchy. As archaeologists continue to analyze the artifacts from this vibrant trade hub, the silent iron restraints offer a sobering counter-narrative to the tales of heroic Gallic warriors, reminding us of the captive lives that helped build ancient Europe's complex trade networks.
Top image: A set of small Gallic offering furniture and a pair of the Celtic iron shackles. Source: © Emmanuelle Collado/Inrap
By Gary Manners
References
Bollard-Raineau, I. 2026. Sacred Offerings at Allonnes. French Ministry of Culture. Available at: https://www.culture.gouv.fr/
INRAP. 2026. Rich Metal Assortment Discovered in Allonnes. INRAP. Available at: https://www.inrap.fr/le-riche-mobilier-metallique-d-allonnes-la-gauloise-maine-et-loire-20820
INRAP 2026. Découverte d'une agglomération et d'un important sanctuaire gaulois à Allonnes. INRAP. Available at: Actualité | Découverte d'une agglomération et d'un importan... | Inrap
Lejars, T. 2026. Celtic Metalwork and Social Hierarchy. Live Science. Available at: https://https/www.livescience.com/archaeology/5-extremely-rare-iron-shackles-discovered-in-france-highlight-celtic-slave-trade-2-300-years-ago
