Ice In The Alps Tells The Story Of Medieval Assassinations And Dirty Air


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

Detail of one of the Becket Miracle Windows in Canterbury Cathedral created in 1180-1220 to mark the shrine to St Thomas Becket. Platslee/Shutterstock

Air bubbles trapped in an Alpine glacier for over 800 years are helping to tell the story of medieval Britain, a decapitated Archbishop, and struggles for power. 

Reported in the journal Antiquity, archeologists from the University of Nottingham have recently studied a 72-meter-long (236-foot) ice core taken from Colle Gnifetti, a glacier in the European Alps on the Swiss-Italian border. By studying the different layers of the ice core, the team were able to learn about the concentrations of atmospheric gases in the air at various times in history.


The analysis showed notable peaks and troughs in air pollution between 1170 CE and 1216 CE. Combined with what we know about atmospheric circulation around this time, the researchers say the spike can be traced back to the mills and mines of Britain, where lead was being furiously smelled for war, as well as to make roof tiles and stained glass windows for the Kings’ ambitious building projects.

Within the subtle variations of lead pollution in the air, the researchers were also able to see echoes of the rise and fall of monarchies. 

“The correlation between evidence of lead production in Britain in the ice core deposits and the tax paid on lead mines is astonishing! We see direct associations between production levels and the workings of government at the time, for example, lead taxation and lead production plummets in the year when a king dies before they are succeeded by another one. This is because medieval governments shut down in the interregnum,” lead author Professor Christopher Loveluck, from the University of Nottingham’s Department of Classics and Archaeology, explained in a statement.

 British lead production, AD 1167–1216, with key historical events labeled. C. Loveluck & A. More

“The ice core shows precisely when one king died, and lead production fell and then rose again with the next monarch. We can see the deaths of King Henry II, Richard Lionheart and King John there in the ancient ice,” Professor Loveluck added.


The traces of lead pollution also neatly lined up with the assassination of Thomas Becket, the Archbishop of Canterbury from 1162 until his death in 1170. In the years before his death, the powerful religious figure was engaged in an infamous conflict with King Henry II. The tensions reached a boiling point on December 29, 1170 CE, when a group of four knights loyal to the king entered Canterbury cathedral and killed Beckett, beheading him in the process. 

By no surprise, the Church was not happy, and the British monarch quickly sought to regain the favor of Pope Alexander.

Speaking to the BBC, Loveluck explains: "To get himself out of jail with the Pope, Henry promised to endow and build a lot of major monastic institutions very, very quickly.

"And of course, massive amounts of lead were used for roofing of these major monastic complexes. Lead production rapidly expanded as Henry tried to atone for his misdemeanors against the Church."


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