Mudlarkers Uncover Historical Relics from Riverbank Sediments

Essential Insights

Henry M. Miller, Ph.D., a Maryland Heritage Scholar, remembers walking onto the muddy banks of the Thames in October 2016 alongside author Lara Maiklem. Maiklem, a contemporary mudlarking expert, had invited Miller to join her in exploring the riverbed for hidden treasures buried beneath layers of historical debris.

While it might seem like a messy task, it was thrilling for Miller, an American historical archaeologist. He was traversing the muddy estuary of southern England with Maiklem to build a comparative collection of London artifacts, aiding in the analysis of early American archaeological sites.

For some, combing through the debris of the Thames might appear unappealing, but it almost always yields fascinating and potentially valuable relics. Discovering items like Roman pottery, a 17th-century tobacco pipe, or a tiny, intact wax seal from the era of King Richard III is what fuels the passion of mudlarkers.

"It's the thrill," Miller says. "You never know what you'll uncover. It mirrors the essence of archaeology—the joy of discovery. What will I find next, and what story will it tell about the past? That's what makes it so exhilarating."

What Is Mudlarking?

If mudlarking is unfamiliar to you, you're not alone. "Most people aren't even aware of the term because it's used by a very niche group," Miller explains. Essentially, mudlarking involves searching through riverbeds for lost or forgotten items.

The practice dates back to the 18th or 19th century, when impoverished individuals, including children, would scour the Thames shoreline at low tide. Miller notes, "They collected nails, bits of coal, or the occasional coin—anything they could sell to buy food."

The Thames was a prime location for such finds. For millennia, it served as a dumping site. "People tossed their daily waste into the river, and the tides would scatter it, making it vanish from view," Miller says. "It was filthy, especially as London's population expanded and the Thames became more contaminated."

In fact, six decades ago, the Thames was so polluted from centuries of waste that it was declared biologically dead. Fortunately, 20th-century cleanup efforts transformed it into one of the world's cleanest rivers. However, its polluted history has made it a hotspot for mudlarking. The riverbed contains thousands of years of debris, from the prehistoric era to modern times. As the saying goes, "one person's trash is another's treasure." Mudlarkers often uncover fascinating artifacts, such as Venetian glass beads, Tudor money boxes, medieval pewter badges, and 16th-century footwear.

While dumping waste into the Thames hid it from view, it didn't vanish. Instead, it settled into the river's muddy bottom. "What's fascinating," Miller adds, "is the anaerobic environment, which preserves materials like wood, bone, cloth, and leather in remarkably good condition." More resilient items, such as pottery, nails, tobacco pipes, and glass bottles, may get tossed around but often remain well-preserved. "I once found a wine bottle top from the late 1700s with the cork still in place," he recalls.

What Makes the Thames Ideal for Mudlarking?

The Thames tides create unique conditions for discovering artifacts that most rivers lack. Its tidal range is remarkably large, rising and falling between 15 to 24 feet (approximately 4 to 7 meters) twice daily. This exposes extensive sections of the riverbed. "In places like the Chesapeake or Hudson, tidal movements exist but are much smaller," Miller notes. "There, it rarely exceeds 3 feet [0.91 meters]."

The Thames tide also moves swiftly, reaching speeds of up to 5 miles per hour (8 kilometers per hour). This rapid flow scours the riverbed, uncovering a wealth of treasures that are carried to the shoreline and left behind as the tide retreats.

Can Anyone Mudlark?

While mudlarking can technically be done along any river worldwide, if you plan to visit England and explore the Thames—or even just walk its muddy shores—you must first obtain a permit from the Port of London Authority. The application process takes at least four weeks and costs around £35 ($43) per day for a Standard License. This license restricts digging to about 3 inches (7.5 centimeters) and requires you to restore the disturbed ground to protect the river's ecosystem.

Safeguarding the foreshore's natural and agricultural resources, as well as ensuring mudlarkers' safety, is a top priority. Consequently, certain areas are off-limits for digging, including the shoreline near the Tower of London and Queenhithe, a historic Roman dock later expanded by Saxon King Alfred the Great in the 8th century.

In the U.S., no permits are needed for mudlarking. While you might discover interesting items, the quantity and quality of finds rarely match those along the Thames. "Sadly, we don't have vast amounts of Roman artifacts here," Miller chuckles.

No matter where you mudlark, there's a chance you might dismiss a valuable artifact as trash or misidentify a worthless fragment as a treasure. In short, uncovering lost treasures requires a keen eye and a solid understanding of historical artifacts.

Recall the wine bottle stopper Miller excitedly discovered during his Thames mudlarking adventure? Many might have dismissed it as rubbish, but Miller recognized its late 18th-century origin due to its design. "Handmade bottles from that era feature a glass string rim just below the neck, used to secure the cork with a cord or wire. The style evolved over time, so identifying the string rim's design helped me date the stopper," he explains.

If you stumble upon an item and wonder about its worth, reach out to your state archaeologist or an archaeologist at a nearby college or university.

Can You Keep What You Collect?

If you imagine mudlarking as a shortcut to wealth, think again. In England, a mudlarking permit grants you the right to collect but also mandates that valuable finds be handed over to authorities for assessment. "England's treasure laws apply to items like gold, silver, or rare artifacts such as a complete Roman sword—these belong to the nation," Miller states.

In England, a Finds Liaison Officer serves as the authority, consulting experts to identify discoveries. These items are cataloged in the Portable Antiquities Scheme, a British Museum initiative to document historical artifacts found in the Thames and across the U.K.

If a mudlarker uncovers something highly valuable, museums have the option to buy it, with the finder receiving compensation, Miller explains. However, many discoveries, such as "tobacco pipes, bottle fragments, pig jaws, medieval pottery shards, or thimbles," he notes, "are so commonplace and mundane that museums already possess vast quantities of them." Once an item is evaluated and determined not to be a treasure, the mudlarker can keep it.

In the U.S., regulations are less stringent, but that doesn't mean you can keep something of significant historical value. "As an archaeologist, I must stress that exceptionally rare items tied to our shared history should be reported to the state historical trust or an archaeologist," Miller advises.