When the Black Death arrived in Europe, it was like striking a match in tinder

The medievalist and historian of medicine Monica H Green tells Ellie Cawthorne how scientific advances have changed our thinking on what caused the Black Death - and why it was so devastating

- Monica H Green

An illustration from the prayer book of Bonne of Luxembourg, who died of plague in 1349. "How did a disease from central Asia kill people in London before aviation?" asks Monica Green

Ellie Cawthorne As a leading expert in the field of Black Death studies, how would you say science has changed the picture for research into this dark episode in human history?

Monica Green I have to be able to talk about the Black Death - it's part of the remit of my job. But the problem with the Black Death was that, for 30 years, there was an intense debate about what caused it. And when you don't know the biological cause of a pandemic, it becomes a black hole in the story that you can throw all kinds of theories into. So I had spent most of my career being frustrated about not being able to tell a coherent story about what was clearly a major historical event.

But in the last couple of decades there's been an absolute sea change, caused by something called paleogenetics. You can now take modern laboratory techniques and apply them to the past - enabling the genetic analysis of molecular material from 100 years, 500 years, and 10,000 years ago. This has allowed us to identify the pathogens that have caused diseases.

Growing concern A doctor lances a bubo in a 14th-century fresco. Science is suggesting that plague has swept back and forth across Eurasia for millennia