A medieval bishop’s seal from the time of William the Conqueror – a metal detectorist find – has been tipped to spark an auction bidding battle.
The scarce copper alloy seal matrix, which is around 1,000 years old, shows a bull being attacked by a lion. It was discovered amid hundreds of objects massed by a metal detectorist over 40 years.
It bears the inscription, WILLEMI DE MARTHAM (seal of William of Martham). Research indicates he was Bishop of Thetford in Norfolk in 1085. Not only that, he was the son of Robert Sire de Belfou, who fought for William the Conqueror at the Battle of Hastings in 1066.
The seal, part of a single-owner lifetime collection, will be offered by Hansons Auctioneers on January 30 with a guide price of £1,500. However, it’s expected to soar past its estimate due to its historical importance.

Hansons said: “Items like this are rarely unearthed so they’re sought after. A previous clergy seal belonging to the Archbishop of Canterbury achieved £5,600 at Hansons but this new find pre-dates that by 300 years. It’s circa 1085, the time when the Bishop of Thetford was granted Martham, a village in Norfolk. This was during the time of William the Conquer who died in 1087.
“It could surprise us under the hammer because bishop’s seals simply don’t come up often. It’s a scarce historical treasure and we owe its discovery to one man’s passion for history.
“It’s part of a lifetime collection of more than 1,000 objects amassed over 40 years by a metal detectorist from Thetford. Sadly, he has passed away. His wife is parting with his finds to ensure they live on as mementos of history. They include hammered medieval coins and numerous ancient artefacts. It’s taken months to sort through and catalogue hundreds of items packed in numerous boxes. The collection is so vast it is being offered in a single-owner sale.
“His passions in life were nature, wildlife and metal detecting. Apparently, he loved anything ancient. He had a particular interest in the Saxon era and medieval seals. He enjoyed researching the objects he uncovered and developed a deep historical knowledge.
The seal must have been one of his most prized possessions.
“It sparked a research trail which revealed there was a Bishop of Thetford called William Beaufoe. Both Martham, in Norfolk and Gunton, in Suffolk, were granted to Beaufoe by William the Conqueror (1066-1087). When Beaufoe died in about 1091 he gave Martham, with many other manors, to his priory at Thetford.
“The connections to Norfolk run deep. The surname Beaufoe originates from the county. William de Beaufou, a Norman Baron, Bishop of Thetford and Chancellor to the Conqueror was recorded in the Domesday Book census of 1086.
“It’s an exceptional find from an exceptional collection, a lasting legacy of a man with a true passion for history.”
The Single-Owner Historica Auction will be held by Hansons Auctioneers on January 30.
Catalogue/bidding: www.hansonslive.co.uk | www.the-saleroom.com
Enquiries/historica valuations: [email protected]