New research involving the University of Liverpool has provided comprehensive insights into the largest flood event in Europe over the past millennium - the flood traditionally known as "St Mary Magdalene's Flood" of 1342.
In Central Europe, the Magdalena Flood was a single catastrophic flood, and the worst flood of the last millennium.
However, the research found that there were in fact a sequence of 16 major flood events across much of Europe covering a two-year period between late 1341 and 1343, and including the July 1342 Magdalena event.
Published in Nature, the new study provides a new details about this series of flood events, revealing to different extents how each of the 16 floods affected communities and regions, and how, together, they had a devastating impact on people across Europe.
The findings highlight the importance of considering the potential for multiple extreme floods to occur in succession when planning for future flood risk.
The study was led by researchers at TU Wien (Vienna University of Technology) and involved a collaboration of researchers from across Europe.
The research team developed a clearer understanding of the 1342 - 43 flood sequence by analysing a wide range of evidence and newly compiled datasets.
These included documentary records, including economic and legal documents, historical sources such as chronicles and the weather diaries of William Merle from Oxford, and comparisons with contemporary floods that affected multiple regions of Europe.
The findings show that the sequence had substantial socioeconomic consequences.
Thousands of people are thought to have died, both directly as a result of the flooding and subsequently through hunger and disease. The floods also destroyed infrastructure and settlements along major rivers and caused extensive agricultural damage, contributing to widespread famine.
In Prague, for example, flooding caused extensive damage to the Stone Bridge, contributing to the eventual construction of the now-famous Charles Bridge, which was designed to withstand substantially greater flood flows.
In exploring the 16 events, they noted that 1342 had highest number of extreme flood events in the last 700 years, and 1343 is a close third.
The researchers believe that this cluster of exceptional floods was not a coincidence, with several possible factors contributing including an unusually high number of volcanic eruptions in 1340 - 41, including the eruption of Hekla in Iceland.
Volcanic eruptions can inject sulphur-containing aerosols into the atmosphere, causing atmospheric disruption and cooling. At the same time, solar activity during the 1330s and 1340s was relatively low. Multi-year changes in Arctic sea ice may also have contributed.
University of Liverpool Professor of Geography Neil Macdonald is a co-author of the study.
He said: "You may ask why we are interested in a series of floods nearly 700 years ago?
"The opportunity to understand the mechanisms that caused so many extreme flood events within a relatively short timeframe provides important information about how climate can be disrupted and the potential consequences. It also enables us to develop a better understanding of contemporary flood risk.
"We recognise that flood events and the mechanisms that generate them are not always independent. As a result, flood risk planning increasingly needs to consider the potential for multiple extreme events occurring in succession and the cumulative impact this could have."
The paper, Cascading continental-scale floods across Europe in 1342 - 1343 (doi:10.1038/s41586-026-10888-8), is published in Nature.
