Decimalisation and the Birth of the Llantrisant Royal Mint
After over a century of avoidance by successive governments, on 1 March 1966, Prime Minister Harold Wilson decisively announced that Britain would transition to decimal currency. This meant that the pound sterling would shift from being worth 240 old pence (d) to 100 new pence.
The impact of this change was especially significant in the South Wales valleys, where a 38-acre site in Llantrisant was developed to accommodate the Royal Mint's increased production demands for the new decimal currency.
Since its establishment, the Royal Mint in Llantrisant has continually evolved, addressing the challenges of a society moving towards cashless transactions by expanding into jewellery, commemorative coins, medals, and even recovering precious metals from electronic waste.
Choosing Llantrisant: A Pragmatic Decision
Once the decision to decimalise was made, the next challenge was determining the location for coin production. Royal Mint historian Chris Barker noted that Belfast and Durham were also considered, but Llantrisant was ultimately seen as "the lesser of several evils."
"From a civil engineering perspective Llantrisant was hopeless - the ground was hilly and boggy, and really difficult to locate heavy machinery."
Despite these difficulties, Llantrisant had several advantages, including its relative proximity to London via rail and the M4 motorway, a workforce experienced in the tin and copper industries of South Wales, and political support from Chancellor and Cardiff MP James Callaghan.
In a rare display of alignment between management and workers, Jack James, deputy royal mint master, expressed concerns that overseas clients might be reluctant to visit Durham. Meanwhile, the London workforce, many of whom would have to relocate, described Llantrisant as "the least obnoxious of all the sites under consideration."
Construction began in 1967, and Queen Elizabeth II officially opened the Llantrisant site in December 1968. By decimalisation day on 15 February 1971, the facility was producing 80% of all new coins.
Historical Roots of the Royal Mint
The Royal Mint traces its origins back to Alfred the Great in the 880s. In 1279, several medieval mints around the St Paul's area were consolidated into the Royal Mint within the Tower of London, which was protected by walls and a garrison.
In the 1810s, the Mint relocated to Tower Hill. However, by the time of decimalisation, the London site was constrained by space and outdated machinery, necessitating a move to a more modern facility outside the capital to meet increased coin demand.
Sir Isaac Newton and the Fight Against Counterfeiting
One of the Royal Mint's most renowned masters was Sir Isaac Newton, a celebrated scientist appointed by William III. Newton engaged in a decade-long pursuit of the infamous coin-clipper and counterfeiter William Chaloner, which ended with Chaloner's execution in 1699.
"Counterfeiting was such an issue because it undermined the public's faith in the coins they had in their pocket," said Barker.
"People such as Chaloner had to be seen to be put to death in order to uphold the value of the currency.
"But Isaac Newton also pursued preventative measures such as the Great Recoinage, whereby centuries-old flat silver coins were recalled in order to remelt them into thicker coins with milled edges, which were far harder to clip, or forge because of their distinctive designs."
Innovations in Coin Design
The Royal Mint has continued to innovate with coin designs that are difficult to counterfeit. The bimetallic £2 coin and the 12-sided £1 coin are considered among the hardest coins in the world to forge.
Among Llantrisant's unique contributions is the "equilateral curve heptagon" 50p coin, proposed by Hugh Conway, managing director of aircraft manufacturers Bristol Siddeley Engines. Its seven-sided design was engineered to tumble through vending machines efficiently.
"It was based on rotary fighter engines designed by Felix Wankel, a German mechanical engineer, whereby when a point was facing down, there would be a flat surface on the opposite side to keep it perpetually rolling," Barker explained.
Commemorative Coins and Rare Exhibits
The Royal Mint's visitor centre showcases a variety of unique items, including commemorative coins struck from bullion recovered from the SS Gairsoppa shipwreck. The ship was sunk by German U-boats off the coast of Ireland 70 years ago while sailing from South Africa to the UK.
Among the rarest exhibits are 1936 Edward VIII coins—prototypes minted before the King abdicated after just 10 months, which never entered circulation.
Adapting to a Cashless Society
With society increasingly moving away from cash, the Royal Mint has faced significant challenges. Even before the Covid-19 pandemic, there was a marked decline in coin usage worldwide.
Having historically provided currency for over 60 nations, in 2024 the Royal Mint did not produce any new coins for the British market for the first time in its history.
To remain viable, the Mint has diversified into commemorative coins and medals, including contracts for events such as the London 2012 Olympics.
"In common with other games, every gold medal was in fact silver, coated in gold-plating, but did contain 8g of pure gold," Barker said.
"The coins and bars we offer depend on the market. Investors, who are looking purely for the financial value can purchase once-struck gold and silver, but for those who place more importance on the designs of our brilliant artists, we offer coins of less purity, but of far more aesthetic appeal."
Reclaiming Precious Metals from Electronic Waste
It may be surprising to learn that the typical mobile phone contains more precious metals than a nine-carat gold ring.
Working with a Canadian company, the Royal Mint extracts significant quantities of precious metals from electronic waste discarded daily.
Barker described this as a "cold chemical process" that avoids melting metals, thereby reducing energy consumption and pollution associated with traditional metal reclamation.
The Mint has launched a jewellery range named 886, after Alfred the Great's first mint, made from wires recovered from devices that might otherwise have ended up in landfill.
"We hope it is the sustainable and profitable future of the Royal Mint," Barker concluded.
