Lost treasures from the Thames to be exhibited at London museum

Twice a day, the Thames flows out into the North Sea, exposing miles of salty clay shores. During these low-tide windows, one of the largest archaeological sites in Britain emerges, and Londoners have long scoured the coast for anything the city has lost, forgotten or thrown away.

The practice is called mudlarking, a term borrowed from the 18th and 19th century mudlarkers who made their living by searching for scraps of metal, rope, coal or anything else that could be sold. It was a job mostly for impoverished children and was backbreaking, dangerous work. The tides could change suddenly, and London factories pumped industrial waste straight into the river.

Today, the tradition of mudlarking is carried on by dedicated hobbyists who seek out artifacts from London’s past, sometimes with the aid of a metal detector. Prehistoric hunter-gatherers relied on the river, as did the Romans, Vikings and Normans, as the Thames was a major artery of communication in Britain from the Middle Ages to the Industrial Revolution. In short, there is much to discover; the anaerobic nature of the Thames’ banks makes it an excellent preservative.

Modern mudlarking is permitted. Mudlarkers can dig (although scraping is better) no deeper than four feet and must report any finds older than 300 years to a special office at the London Museum, which then records and examines the objects. The process will be explored at the museum as part of “Secrets of the Thames: Mudlarking London’s Lost Treasures,” the first major exhibition devoted to the tradition, opening in 2025.

The exhibition builds on decades of collaboration between the museum and the mudlarking community, which has grown in 2020. “We have built an incredibly significant collection that is housed in the museum,” said curator Kate Sumnall, who has worked with the mudlarkers for almost 20 years. “We have tried to capture the thrill of discovery, the meditative nature of the search and the connection to the past that the Thames offers.”

It’s a travelling exhibition that explores different moments in London’s history, one discovery at a time. Each object evokes a cultural moment in time and the spectre of the person who once owned it.

The oldest artifact is an early bronze flint arrowhead that dates back 3,000 years. Another weapon on display is a 10th-century iron dagger known as a scramasax, from which the Saxons get their name. It is an elaborate piece, inlaid with silver and marked with the owner’s name, Osmund. Later still is a 16th-century whistle used by a naval officer to communicate over the roar of wind and waves (the pitch can be changed). It is made of tin and has a lion whose tail bends into a convenient loop.

Elsewhere, we come across domestic discoveries. There is a 15th or 16th-century toy cauldron that is an exact replica of those placed over an open fire to cook food. There is a pair of late medieval spectacles designed to fit snugly over the nose and serve both nearsightedness and farsightedness. There is a set of early 18th-century false teeth made of carved ivory. They were custom-made and must have been incredibly expensive, the museum noted.

Perhaps the most unusual, given its material and age, is a 500-year-old wool Tudor cap. It is an inexpensive imitation of the velvet versions that were fashionable among upper-class women. Few of these caps have survived.

“There are traces of everyday life,” Sumnall said. “The food they ate, the clothes they wore, their faith, their skills and their trades. These small observations add up to a bigger picture of London.”

Thames Secrets: Digging in the Mud for London’s Lost Treasures is at the London Museum Docklands, 1 West India Quay, Hertsmere Road, London, from 4 April 2025 to 1 March 2026.