Michael Leigh-Mallory found the 13th-Century coin on the first day of using his new metal detector. He had enjoyed the detecting hobby before but had given it up when his children were born. He is now 52, and his children are now 13 and 10, respectively; it was they who encouraged him to get back into it.

Leigh-Mallory, a retired ecologist, is also an amateur historian and so knew that what he found, in the village of Heymock, was rare. However, when he took the coin to the British Museum, experts there told him that the coin was only of eight in existence and that the last one was found more than 250 years ago.

According to the experts, the coin was made in the reign of Henry III, who reigned in 1216–1272. Historians say that about 52,000 of the coins were made. The king features on the front of the coin; on the back are roses and a cross. Only eight of the coins remain; the other seven are in museums.

The auctioneers Spink and Sons sold the cold, made in North Africa, at a London auction for a total price of £648,000, which is US$878,778. A private collector bought the coin, in the process paying the highest price ever for a coin in the United Kingdom.

Leigh-Mallory said that he would split the money with the owner of the land in which the coin once lay and that he would use his share to help finance the education of his children, one of whom plans to study and the other of whom plans to study archaeology. Leigh-Mallory completed another related activity when he made a pilgrimage to the tomb of Henry III, who is buried in Westminster Abbey.