The Shapwick Hoard at the Museum of Somerset, Rodw, Wikimedia Commons, CC BY-SA 3.0.
In 1998 two cousins detecting a ploughed field in Somerset found 9,238 Roman silver denarii, one of the largest hoards of denarii ever found in Britain. Excavation showed they had been buried under the floor of an unknown Roman villa.
On 14 September 1998, cousins Kevin and Martin Elliott were metal detecting in a ploughed field at Shapwick, on the Polden Hills in Somerset. Their first coin was near the edge of the field. Following the line of the plough furrow across it, they found a group of about 70 coins, and half an hour later the hoard itself.
It contained 9,238 Roman silver denarii, though other published totals differ slightly. The earliest were struck for Mark Antony's legions around 32 BC, and the latest under the emperor Severus Alexander in about AD 224, which dates the burial. Among them are two coins of Manlia Scantilla, wife of Didius Julianus, who ruled for only a couple of months in AD 193. Most of the coins are in remarkable condition.
About 9,000 of the coins were still where they had been placed, standing on edge in neat rows, which suggests they had been packed in rolls of cloth or leather inside a bag. The finders reported the discovery, and geophysical survey and excavation then revealed that the coins had been buried beneath the floor of a room in a Roman courtyard villa that nobody had known existed.
The hoard was declared Treasure and acquired in 2000 by the Somerset County Museum in Taunton, now the Museum of Somerset, with grants from the National Heritage Memorial Fund and the Art Fund. The total cost was £265,000.
Written for Global Finds from the National Heritage Memorial Fund, the Art Fund, the Journal of Roman Archaeology and other published accounts. Photo: the Shapwick Hoard at the Museum of Somerset, Rodw, Wikimedia Commons, CC BY-SA 3.0.
Those four are for England and Wales, where the Portable Antiquities Scheme records finds and the Treasure Act decides what must be reported.
Scotland runs its own system, and every find is reportable there — not only treasure. Treasure Trove Unit ›
The Republic of Ireland is different again, and severely so. Searching for archaeological objects without the Minister’s written consent is a criminal offence carrying fines or imprisonment, and the definition is broad enough to cover coins, buttons and buckles of almost any age. Do not assume British rules travel with you. The law, from the National Museum ›
Northern Ireland is stricter still. The Treasure Act applies and finds go to National Museums NI within fourteen days, but any searching that involves digging — metal detecting expressly included — needs a licence, and licences are only granted for archaeological projects. National Museums NI ›
This site covers discoveries from all over the world, and so does the variation in the law — from a recording scheme that thanks you, to a criminal offence. Wherever you are searching, find out what applies there before you go, not after.