Archaeologists and forensic scientists who have examined 25 skeletons unearthed in the Clerkenwell area of London a year ago believe they have uncovered the truth about the nature of the Black Death that ravaged Britain and Europe in the mid-14th century.

Analysis of the bodies and of wills registered in London at the time has cast doubt on "facts" that every schoolchild has learned for decades: that the epidemic was caused by a highly contagious strain spread by the fleas on rats.

Now evidence taken from the human remains found in Charterhouse Square, to the north of the City of London, during excavations carried out as part of the construction of the Crossrail train line, have suggested a different cause: only an airborne infection could have spread so fast and killed so quickly.