Lead mining & politics - 12thC

Alpine ice sheds light on 12th century lead pollution and politics:

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.

Analysing the 800 year-old ice using a highly sensitive laser, the scientists were able to see a huge surge in lead in the air and dust captured in the 12th century. Atmospheric modelling showed that the element was carried by winds from the north west, across the UK, where lead mining and smelting was booming in the late 1100s. Lead had many uses in this time, from water pipes to church roofs to stained glass windows.

Lead and silver are often mined together and in this period, mines in the Peak District and in Cumbria were among the most productive in Europe. The researchers were able to match the physical records from the ice with the written tax records of lead and silver production in England.

In the 1169-70 period, there was a major disagreement between Henry II and Thomas Beckett. The clash resulted in the Church's refusal to work with Henry - resulting in a fall in lead production that year. Excommunicated by the Pope in the wake of the murder of Thomas Beckett, Henry II attempted a reconciliation with the Pope. 

"Henry promised to endow and build a lot of major monastic institutions very, very quickly. Massive amounts of lead were used for roofing of these major monastic complexes. Lead production rapidly expanded as Henry tried to atone for his misdemeanours against the Church.

The researchers say their data is also clear enough to show the clear connections between lead production rising and falling during times of war and between the reigns of different kings in this period between 1170 and 1220.