The destructive force unleashed by Vesuvius, Krakatoa, and Mount St Helens made those volcanoes household names. Yet all three are dwarfed by the largest eruption of the last millennium. It violently ejected between 200 and 600 megatons of sulphate into the Earth’s atmosphere, around eight times the yield from Krakatoa. Probably occurring in early 1258 AD, this was an eruption on a cataclysmic scale.
Despite its magnitude, the identity of the volcano responsible remains a mystery. El Chichón in Mexico, Quilotoa in Ecuador, and, most recently, a site in Indonesia have all been named as possible culprits. But while the source of the sulphates remains elusive, the eruption’s fingerprints can be found around the globe. Ice cores from both the northern hemisphere and Antarctica preserve its debris, while a thick layer of ash lies among the sediments in Lake Malawi, nestled between Mozambique and Tanzania. Traces can even be found in the records of contemporary chroniclers writing far from the tropics.
The unseasonableness of the atmosphere
Wherever the volcano lay, Matthew Paris was living thousands of miles away when it blew – a Benedictine monk writing in St Albans abbey. His Historia Anglorum covers the period from 1250-1259, and intersperses commentary on contemporary events with observations on that most British of obsessions: the weather. Paris was perplexed and troubled by what he saw in 1258. The year got off to a bad start, with the monk recording ‘such unendurable cold, that it bound up the face of the earth, sorely afflicted the poor, suspended all cultivation, and killed the young of the cattle’. But that was just the beginning. As the year progressed the situation deteriorated, and by midsummer Paris had cause to put pen to parchment once more:
