Matthew Flinders is barely 40, but he looks 70. His once dark hair gleams white, his already slight frame skeletal. As a captain in the British Royal Navy, he’s survived shipwreck, imprisonment, and scurvy, but this kidney infection will do him in. Facing death, he finishes writing a book that will change the world as Europeans know it. Flinders completed the first circumnavigation of the “Terra Australis Incognita,” or “Unknown South Land,” in 1803. A decade later, he compiles his writings, maps, charts, and drawings of the rugged coasts, extensive reefs, fertile slopes, unusual wildlife, and other features of the faraway continent that he suggests naming “Australia.”

His wife places a copy of the freshly printed book, A ­Voyage to Terra Australis, in his hands as he lies unconscious in their central London home the day before his death in July 1814. Later, he’s interred at St. James’s burial ground, but within a few decades, the tombstone is missing. When the railways at nearby Euston Station expand in the mid-1800s, workers re­locate, pave over, or strip graves. Lost in a subterranean terra incognita, the explorer might lie somewhere under track 12. Or 15. Or the garden that’s replaced the cemetery. No one knows.

Today, a bronze Flinders at the station entrance crouches over a map alongside his beloved cat Trim, who also made the trip around Australia. If the statue could lift its head, it would see commuters rushing across the plaza past construction barriers. The hub is expanding again, now as a new terminus of the huge HS2 high-speed rail project, which will connect the capital with points north.

This time, though, a team is carefully exhuming and ­documenting remains before the tunnel-boring, track-­laying, and platform-building begins. They know that Flinders and an estimated 61,000 others were buried here between 1789 and 1853. But, with only 128 out-of-place headstones ­remaining, they don’t know who they’ll find.

Caroline Raynor, an archaeologist with the construction company Costain, leads the excavation. On a typically overcast day in January 2019, she oversees work beneath what she calls her “cathedral to archaeology,” a white bespoke tent so massive that it could house a Boeing 747. It shields a hard-hat-clad crew of more than 100—and the dead, sometimes stacked in ­columns of up to 10 as much as 27 feet deep.

Where the London clay is waterlogged and ­oxygenless, delicate materials survive. ­Clearing earth by hand and trowel over the course of a yearslong job, Raynor’s diggers uncover ­bodies wearing wooden prosthetics, as well as the Dickensian bonnets that used to hold the deads’ mouths closed. One man still sports blue slippers from Bombay. Even plants and flowers remain. “Some of them were still green,” Raynor says.

Suddenly, a crewmember runs over with news about a grave fairly near the surface. Very little of the coffin is intact—wood doesn’t fare well in the granular, free-draining topsoil—so there’s nothing to open. A lead breastplate rests atop a bare skeleton: “Capt. Matthew Flinders R.N. Died July 1814 Aged 40 Years.”

The discovery is one small chapter in the saga the HS2 project promises to tell. If the first stage of the $115 billion initiative is fully realized, the train will cut through ancient woodlands, suburbs, and cities along the 143 miles between Birmingham in the north and London in the south—though not before teams like Raynor’s uncover any underground treasures. “It looks like we’re finding archaeology from every phase of post-glacial history,” says Mike Court, the archaeologist overseeing the more than 60 planned digs for HS2 Ltd., the entity carrying out the rail initiative. “It’s going to give us an opportunity to have a complete story of the British landscape.”

With more than 1,000 scientists and conservators involved, the scale of HS2’s excavations is unprecedented in the UK, and perhaps all of Europe. However, it’s hardly an outlier. As ­development continues to tear through hidden civilizations across the continent, investigations like this are becoming common; in fact, they’re often required by legislation. While researchers once bored trenches exclusively on behalf of museums and universities, many now work on job sites. These commercial archaeologists dig up and analyze finds for private companies like the Museum of London Archaeology (MOLA), a primary contractor on HS2. Because their work is tied to the pace and scale of building projects, their targets are quite random, and discoveries can be boom or bust. Sometimes they’ll unearth just a few graves during housing construction; other times they’ll turn up dizzying amounts of data on battlefields and cemeteries in the path of huge public works.

When efforts at Euston wrapped in December 2019, Raynor’s crew had uncovered some 25,000 of the boneyard’s residents, including ghosts like ­auction-­house founder James Christie and sculptor Charles Rossi, whose caryatids watch over the nearby Crypt of St. Pancras Church. Gazing at the site from her makeshift office, Raynor marvels at the scope of the work still ahead: “It’s very difficult to dig a hole anywhere in the UK without finding something that directly relates to human history in these islands.”

UK construction dig sites
More than 60 excavation sites dot the first phase of the HS2 rail project. Violet Reed

Construction and archaeology weren’t always so close-knit. Through much of the 20th century, builders in the UK often haphazardly regarded artifacts and ruins. Sites were rescued only by the goodwill of developers or ad hoc government intervention.

The chance discovery of the Rose in the late 1980s spurred England to adopt new rules. Among the brothels, gaming dens, and bear-baiting arenas on the south bank of the River Thames, the Rose was one of the first theaters to stage the works of William Shakespeare, including the debut of Titus Andronicus. The construction team had the right to pave over it after only a partial excavation, and the government wasn’t eager to step in to fund a preservation.

Actors like Sir Ian McKellen, Dame Judi Dench, and Sir Laurence Olivier joined calls to save the 16th-century ­playhouse. At 81, Dame Peggy Ashcroft was on the front line blocking bulldozers. The builders wound up saving the theater, spending $17 million more than planned.

To avoid future conflicts, in 1990 the country adapted a “polluter pays” model for mitigating harm to cultural heritage. Now developers must research potential discoveries as part of their environmental-impact assessment, avoid damaging historic resources, and fund the excavation and conservation of significant sites and artifacts.

That tweak led to “vast changes” in the UK, says Timothy Darvill, an archaeologist at Bournemouth University in England. “Just the sheer number of projects that were undertaken increased manifoldly.” According to his research, thousands of digs occurred per year in Britain from 1990 to 2010, increasing tenfold from decades prior.

Other governments followed suit. Most European countries have signed the 1992 Valletta Convention, a treaty that codified the practice of preservation in the face of construction. Findings published by the ­European Archaeological Council in 2018 show that developers now lead as much as 90 percent of investigations on the continent.

Archaeologists have opportunities to uncover enormous swaths of history on sites that logistically and financially might have been inaccessible before—especially in the course of major civil-engineering initiatives. ­Infrastructure authorities have funded multimillion-dollar projects to turn up mass graves on Napoleonic battlefields in the path of an Austrian ­highway, and 2,000-year-old ruins under Rome during a subway expansion.

Before HS2 became Britain’s banner big dig, Crossrail was the nation’s largest such program. Beginning in 2009, efforts ahead of the 73-mile train line across London revealed thousands of gems at 40 sites: fragments of a medieval fishing vessel, Roman skulls, a Tudor-era bowling ball, and 3,000 skeletons at the graveyard of the notorious Bedlam mental asylum.

To carry out all this work, many nations have competitive commercial markets for research and excavation. MOLA, an offspring of the Museum of London, is one of the largest British firms, and HS2 is one of its major clients. Its field crew surfaces thousands of objects destined for ­cataloging by a team of staffers on the other side of town.

MOLA headquarters sits in an old wharf building on the edge of a canal in East London’s Islington borough. The ground-floor loading bay leads to a labyrinth of rooms of dusty 20-foot-high shelves packed with dirt-caked finds trucked in from the field. Pallets and containers full of architectural stones, pottery fragments, and tubes of sediment flank narrow aisles. Thanks to the glut of construction-backed excavations, spaces like these see a constant flow of goods demanding attention.

In a small office near the maze, a researcher holds a human skull. Alba Moyano Alcántara is a “processor,” using a paintbrush to dab away soil on the centuries-old ­cranium. Like a triage nurse, she’ll decide the next steps for these remains and other artifacts. Damp bones will dry slowly on racks in a warm room down the hall; pieces of metal get X-rayed to reveal their original forms.

Eventually, they’ll head upstairs, where MOLA’s specialists catalog the ­minute ­details of the finds. In an open-plan ­office, ­senior osteologists Niamh Carty and ­Elizabeth Knox inspect a pair of ­incomplete skeletons. Carty studies the top half of a young woman; Knox, the bottom half of a man. Truncated ­bodies are common in old boneyards, where new graves often cut into old ones. Confidentiality agreements with clients keep the researchers mum on the exact origin of the remains, but they offer that these are from a “post-medieval ­cemetery.” If it wasn’t St. James’s, it was a place like it.

The thousands of skeletons that pass through MOLA contribute to a database of London’s population-wide rates of pathology, injuries, and other bioarchaeological information from prehistory to the Victorian era. “Every skeleton we look at is adding to the bigger picture,” Carty says.

She lingers over a rotted-out tooth, which likely caused a painful abscess before this young woman died. Knox’s skeleton’s lower legs have an irregular curvature, perhaps a sign that he suffered from rickets in his youth; his spine has Schmorl’s nodes, ­little indentations on the vertebrae created by age or manual labor. “Archaeologists probably all have them,” Knox quips.

Sometimes a small sample can shed light on nationwide phenomena. The Crossrail dig uncovered a burial pit from the 17th-­century Great Plague of London, which killed nearly one-quarter of the population. In teeth from that site, researchers discovered the DNA of the bacteria that caused the outbreak. Analysis of all the HS2 remains might one day reveal migration and disease patterns from the Middle Ages to the Industrial Revolution.

MOLA employees also gain insight from individual artifacts. Across the office, Owen Humphreys and Michael Marshall—­so-called finds specialists—study ­uncommon relics weeded out from the pottery pieces, nails, animal bones, and other abundant objects destined for bulk inventorying. “I once likened our job to being the seagull in The Little Mermaid,” Humphreys says. “People bring us things, and we take a wild stab in the dark as to what they are—”

“—a very well-informed stab,” Marshall adds. He holds the wooden leg of a Roman couch found on the Thames waterfront, its paint still red nearly 2,000 years later. “You very rarely get things like this in Britain,” he says. “It’s lucky that we got an opportunity to find out a bit more about what people’s homes looked like.”

These inspections can help determine the objects’ fates. The Museum of London houses the world’s largest archaeological archive of more than 7 million items from more than 8,000 excavations awaiting further study, placement in a collection, or, in the case of the St. James’s bones, reburial. A precious few finds will earn spots on public display.

skeleton discovered during construction
An archaeologist carefully cleans one of the thousands of bodies uncovered in St. James’s burial ground in London. Adrian Dennis/AFP via Getty Images

Leather shoes, wooden combs, an amber carving of a gladiator’s helmet, and some 600 other Roman artifacts adorn the ground floor of Bloomberg LP’s new ­European headquarters in central London. The nine-story structure sits on the site of a 3rd-century Roman temple dedicated to the god Mithras. First discovered during construction of an office building in the 1950s, the Mithraeum suffered an infamously botched reconstruction deemed “virtually meaningless” by the site’s lead archaeologist.

After MOLA reexcavated in 2014 on behalf of Bloomberg, the developers had another shot to tell the temple’s story. Now visitors descend several flights of stairs into a darkened room. Light and mist create the illusion of complete walls extending from the stubby foundations of the subterranean temple. Footsteps and ominous Latin chanting piped in from the speakers crescendo, transforming this ruin into the site of secret cult rituals.

To be sure, many builders see ­archaeology as a compulsory, time-consuming, and expensive hurdle. There’s little publicly available information on the costs for these investigations, even for HS2, but according to the research of Bournemouth archaeologist Darvill, digging might add an extra several million dollars, depending on the scope of the plans. Still, the flashy new Mithraeum is evidence that some have found a symbiosis in using the past to try to make their projects more palatable to locals. Across the city in Shoreditch, a once-gritty East London neighborhood now synonymous with gentrification, the remains of a 16th-century Shakespearean playhouse called the ­Curtain Theatre will be incorporated into a new ­multipurpose development. According to the ad copy, the Stage will be an “iconic new showcase for luxury living,” and the “first World Heritage Site in East London.”

The archaeology story of HS2 will be too sprawling to fit neatly in a basement or lobby. It will take years to process and analyze all its finds. As of fall 2019, only the two biggest digs had finished: St. James’s and the excavation of another 6,500 graves from an Industrial Revolution-era cemetery at the Birmingham station.

HS2 archaeologists are now running test trenches to decide precisely which spots they’ll uncover in between. “Some of them are once-in-a-generation archaeological sites, and some are smaller, still interesting, but not large scale,” says project field lead Court. We already know that HS2 will cut through a mysterious prehistoric earthwork called Grim’s Ditch in the hills outside London, and farther north, a Roman town and a millennia-old demolished church. Researchers also hope to find traces from the Battle of Edgecote Moor, which broke out in Northamptonshire in 1469 during the Wars of the Roses.

The fate of HS2’s archaeological ­ambitions, however, is entangled with what has become an increasingly unpopular infrastructure project. Prime Minister Boris Johnson ordered a review to determine whether the rail should be scrapped because of ballooning costs and delays. Critics argue that the benefits won’t outweigh the environmental disruption, the land seizures, and the financial burden to taxpayers. The community around Euston Station protested the construction, which gouged a green space, and leveled homes, offices, and hotels, displacing longtime residents who complained about shoddy compensation. The vicar of a nearby church even chained herself to a tree.

In such a controversial effort, any incidental cultural benefits are bound to conjure a degree of suspicion. “I’m fascinated by the stories that the dig at St. James’s Gardens is helping to bring to light,” says Brian Logan, the artistic director of the Camden People’s Theater, located at the doorstep of the site. “But I think you can be enthusiastic about archaeology while being a little skeptical of the purposes to which it’s being put.” In the first act of a 2019 performance that dealt with those issues, Logan knocked the project’s PR department for casting the rail as a bonanza for discovery: “Is archaeology really a profession we want to run on a bonanza basis?”

In the era of developer-led digging, that’s a question practitioners are reckoning with too. Costain archaeologist Raynor, whose focus now turns from St. James’s to the 15 miles of track leading out of Euston Station, would at least agree that her profession lacks sustainability. According to Darvill, half of archaeologists work in jobs tied to construction.

Bonanza-like conditions also create a gold rush of information—a blessing and a curse. With overstuffed basements, museums around the world face a storage crisis, and more digging might only compound the problem, especially now that archaeologists consider sites as recent as World War II worthy of study. Raynor sees the management of all that information as the bigger ­challenge—not just for scientific analysis, but also for public consumption. The excavation at St. James’s alone generated 3.5 terabytes of data. “It loses meaning if you don’t communicate it,” she says.

Luckily, communication is the easier piece of the puzzle. In Raynor’s experience, people viscerally react to pots, bowls, tools, and other bric-a-brac from the past. “As ­human beings, our wants, needs, and ­desires ­haven’t changed that much,” she says.

While the saga of HS2 is still being ­written, those small finds might resonate as much with the public as the ­discoveries of icons, like Matthew Flinders, whose life stories are embedded in the UK’s ­ever-changing stratigraphy. Flinders ­himself wouldn’t recognize Euston Station today, nor would he have thought he’d be an interesting ­scientific specimen. For better or worse, he helped chart a course through history, only to find himself in its path.

This story appears in the Spring 2020, Origins issue of Popular Science.