Four letters, ANCE, open a brass combination lock recovered from the Ann Frances, an English merchant ship that sank off Wales in 1583. David Williams, a research associate in Cardiff University’s School of Engineering, found the word by building a micro-CT image of the lock’s internal mechanism. A team from Amgueddfa Cymru, Museum Wales, tried the letters later the same day, and the lock opened.
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What the word meant to the person who set it, and what the chest behind it held, nobody has yet been able to say.
Reading the notches without opening the case
Williams used micro-CT scanning, a technique normally applied to bones and other biological structures, according to Nation.Cymru, and scanning a 400-year-old lock was a first for his team. The resulting three-dimensional image showed how notches inside the mechanism lined up with the letters on its rings, which let him read the combination without forcing anything. Williams told reporters that watching for the museum team’s test was incredibly satisfying once he learned the lock had opened. Archaeology Magazine’s Jessica Esther Saraceni reported the result on Nov. 5, and the work is described in a Cardiff University news release.
The object itself is modest in size and remarkable in condition. Peter Hughes, the metal detectorist who found it, recalled being astonished by the workmanship and by the fact that the lettered rings still turned easily. The museum’s online collection record lists it as a copper alloy lock from Morfa Beach, Margam, associated with the 1583 wreck, and notes that combination locks of this type from the sixteenth century are common finds in general. What sets this one apart is the dated wreck behind it.
The scan matters beyond the single word. A mechanical combination lock of this period hides its secret inside a closed brass case, and the usual ways of learning it, trying letter after letter or opening the case, risk wearing or breaking a 440-year-old object. Imaging the interior left the lock intact, and it still sits among the hoard on public display. Williams’s colleagues in the museum could verify the answer on the actual object within hours, which turned a laboratory reading into a confirmed result.
The Ann Frances and the storm of Dec. 28, 1583
Museum records spell the vessel Ann Francis, Anne Francis or Ann Frances, depending on the page. According to the museum’s press office, the merchant ship was returning from Spain when a storm blew it off course on the evening of Dec. 28, 1583, and it was wrecked on Margam beach near Port Talbot. Its owner, Francis Shaxton of King’s Lynn, had sent a cargo of grain to Spain, and he lost both the ship and the payment for the cargo.
Most of what survives was recovered by Hughes over 21 years, between 1996 and 2017, after dredging and storms stripped sand from the beach and exposed objects beneath it. The finds include gold coins from the reign of Ferdinand and Isabella of Spain, a boatswain’s whistle, Spanish silver coins and two coin weights, and the lock. Amgueddfa Cymru acquired the hoard with Welsh Government support. It went on public display at the National Waterfront Museum in Swansea in the Tides of Treasure exhibition, which opened on 26 June 2026 and runs until June 2027.
The Tides of Treasure display places the lock among accounts of sailors, looters, lords, a smuggler and a woman accused of witchcraft, according to the museum’s press office, so the lock sits in a wider story of this stretch of Welsh coast. The finds also show how much trade ran between Wales and Spain in the 1580s: grain went out, and gold and silver coins from the reign of Ferdinand and Isabella came back on ships that did not always make it home.
What ANCE might have protected
Alastair Willis, senior curator for numismatics and the Welsh economy at Amgueddfa Cymru, said the lock’s exceptional condition and its link to a dated wreck make it unique. He added that now the code is solved, curators are left wondering whether the four letters meant something to the owner. No source offers a reading of ANCE, and the museum has not suggested one.
The lock is believed to have secured a small chest found near the Spanish silver coins, so the chest may have held coins or other valuables. Archaeology Magazine notes that the chest’s contents have not survived. Nation.Cymru adds that the chest may instead have held perishable goods such as documents or textiles, which would leave no trace after four centuries in sand and seawater. Coins and weights found close by point toward money, but nothing recovered settles the question. Until a second source turns up, the meaning of ANCE stays a question about one sixteenth-century owner and the word chosen to guard the chest.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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