A team of 60 archaeologists have started excavating around 3,000 skeletons from the Bedlam burial ground near Liverpool Street Station in London.
The burial site was used from 1569 to 1738, including the time of the Great Plague in 1665.
Test on the excavated skeletons will help understand the origins and evolution as the plague spread.
The Bedlam burial ground is at the site of the new Liverpool Street station that will serve the cross-London Crossrail line.
A team of 60 archaeologists will work in shifts, six days a week to remove skeletons and carefully record evidence for what may prove to be, in archaeological terms, London’s most valuable 16th and 17th-century cemetery site.
Crossrail lead archaeologist Jay Carver said: “This excavation presents a unique opportunity to understand the lives and deaths of 16th and 17th century Londoners.
“The Bedlam burial ground spans a fascinating phase of London’s history, including the transition from the Tudor-period city into cosmopolitan early-modern London.”