The flow of traffic between London and Essex has recently included a regular consignment of 400- year-old human skeletons.

For them, unlike others who make the trip, the journey has been strictly one way.

The old bones are headed for a new home at Willow Cemetery, on Canvey Island.

First, though, there is work to do. Before their journey to Essex, the bones have secrets to yield up.

The human remains are being reinterred from the City of London’s old Bedlam graveyard, just a few yards from where travellers chomp burgers at the Liverpool Street McDonald’s. Millions of City workers have criss-crossed this spot down the decades, blissfully unaware of the world of bones that lies just beneath their feet.

Now the ground has been dug away by blokes in hard hats, and the bones lie exposed beneath a translucent awning.

Teams of archaeologists examine these mortal remains with an attentiveness they never commanded when they were sentient human beings.

The cemetery lies across the path of Crossrail, the trans- London train route, so the 3,000-odd skeletons must upsticks and find a new place to lay down their weary skulls.

First, though, they are being examined, and what they reveal could transform understanding of London’s history.

“This is a unique project,”

says the man in charge of the operation, lead archaeologist Jay Carver. “It’s our first chance to examine the contents of a municipal burial ground in the heart of London.”

The Bedlam burial ground was set up at the behest of the Lord May of London in 1569.

London was expanding at a furious rate, not for the first or last time. The living population was burgeoning, and so, by natural extension, was the deceased population.

The old parish graveyards could not cope.

Jay explains: “It was the final destination for people from around London who could not afford a church burial, or who chose to be buried there for religious or political reasons. They represent a hugely diverse population from right across the social spectrum, and from different areas of the City. By studying in detail, we hope to gain a great deal of information about the demography of London during the Tudor and Stuart periods.”

The site was also used intensively at times of mass epidemics, notably the notorious “bring out your dead” period of the Great Plague of London in 1665.

Over 100,000 people died in the city. At such times, notions of an orderly burial went out of the window. The evidence of this lies in the sprawling, higgledy-piggledy positions of many of the skeletons “Forget any ideas about rows of neat, straight lines of grave plots,”

says Jay. The average body count is eight per square metre.

The research being done on these remains is not merely academic.

It could have major significance for public health among the living of the 21st century.

Jay cites the case of the Great Plague. “What caused the outbreak, and why did it rage so fiercely, and then just disappear? The Bedlam site give us a means of diagnosis that wasn’t available before.

We can identify with precision the bacteria that was in a body at the moment of death.”

The giveaway lies in the teeth. “The dental pulp contains the DNA imprint of the bacteria,” says Jay. “The pulp is protected by the enamel. The bacteria are no longer alive, but they have left this key to their identity. It has split into many thousands of fissures, but it can still be recovered.” Four centuries later, the dental pulp is being DNA analysed by experts at the University of Ontario in Canada, a nation which did not even exist at the time these bones were laid to rest.

Once their work is done, the bones are sent to be reinterred on Canvey Island. Why Canvey? “The exhumation contract was won by T J Cribb,” says Jay. Founded in 1881, Cribb has served the East End throughout two world wars, and has long experience of mass burial sites, both ancient and modern. As well as London, it also has branches at Benfleet and Pitsea. The Willow cemetery is privately owned by Cribb, and it is here that the Bedlam bones will find their final final resting place.

As for Jay and his team, having said goodbye to the bones, they will be digging deeper. Beneath the graveyard lies evidence of the medieval water meadows of the lost River Walbrook. “After that, we get to Roman London,” says Jay.

In 2018, when Crossrail opens, part of the cemetery site will be occupied by the new Liverpool Street booking office, and the rest re-covered by a new pedestrian walkway.

Once again, City of London workers will pass oblivious to what lies beneath. “We’re hoping to put a plaque into the paving as a reminder of what was here, though you wonder howmany people will notice,”

says Jay.

The Bedlam skeletons themselves will be past caring, as they lie back in their new home on the Essex marshes.

Jay points out that there is already a precedent. “When London was expanding in the 19th century, the City of London Cemetery was set up in Essex in 1853 to take the overflow.”

London bones, Essex soil.

“It’s part of a long tradition,”

he says.