The Thornbury Treasure is a significant hoard of Roman coins discovered in Ken Allen Gardens in Thornbury, South Gloucestershire, England, during March 2004. This remarkable find consists of 11,460 copper alloy Roman coins, with the majority being radiated and NUMMI coins. These coins date from the years 260 to 348 AD.
The discovery of the Thornbury Treasure was made by Ken Allen while he was excavating a pond in his garden. The coins were found within a rough gray vessel that was decorated with ware. The vessel measured approximately 40-50 cm (16-20 inches) in height and is believed to have originated from Caldicot, Monmouthshire. Unfortunately, the vessel had been damaged during the excavation process.
Ken Allen reported his discovery to the authorities, and the coins were taken to the Bristol City Museum and Art Gallery. Once there, they underwent drying and chemical treatment, making it easier to identify and catalog them. In total, the hoard weighed a substantial 28.6 kg (63 pounds), and it reportedly took two men to lift the bucket containing the coins.
After a formal investigation, a coroner declared the Thornbury Treasure to be a genuine treasure. Subsequently, an appraisal committee estimated its value at £40,000. The Bristol City Museum and Art Gallery acquired the hoard using funds from various sources, including the Heritage Lottery Fund, the Headley Museums Treasure Acquisition Scheme, and other organizational funds. This acquisition allowed the treasure to be preserved and made available for public display and study.