Ancient air pollution, trapped in ice, reveals new details about life and death in 12th Century Britain.
In a study, scientists have found traces of lead, transported on the winds from British mines that operated in the late 1100s.
Air pollution from lead in this time period was as bad as during the industrial revolution centuries later.
The pollution also sheds light on a notorious murder of the medieval era; the killing of Thomas Becket.
Becket, though, had other plans.
Henry's growing irritation with his Archbishop led the King to reportedly utter the infamous phrase: "Will no one rid me of this turbulent priest?"
Unfortunately for Becket, a group of knights loyal to the King decided to make Henry's wish come true.
Becket was beheaded in a brutal attack at Canterbury cathedral on 29 December 1170.
Now scientists have found physical evidence of the impact of the dispute between Henry and Becket in a 72-metre-long ice core, retrieved from the Colle Gnifetti glacier in the Swiss-Italian Alps.
In the same way that trees detail their growth in annual rings, so glaciers compact a record of the chemical composition of the air, trapped in bubbles in the yearly build-up of ice......