The worst flood disaster in Europe took place in 1342

The original article can be read as “Schlumpfs graphic 121” in the online Nebelspalter of 29 July 2024.

After a summer of rivers and streams bursting their banks due to torrential rain, many people are wondering whether this is still “normal”. Or whether, with rising temperatures as a result of climate change, such events will become even more frequent and devastating in the future. However, a look at the storm archives of the last millennium shows that the worst flood disasters did not occur in the recent past, but in earlier centuries.

What is important:

– In the summer of 1342, the so-called Magdalene Flood, the millennium flood of our time, occurred in Europe.
– The rivers Main, Rhine, Weser, Elbe and Danube have never been so full since.
– This catastrophic flood took place during the transition from the Medieval Warm Period to the Little Ice Age – immediately before the largest plague epidemic in Europe.

A video by the Austrian ski tourist researcher Günther Aigner entitled “The Millennium Flood of 1342”, which is based on excellent research, inspired me to write this article (see here).

In a chronicle of the city of Würzburg (see here) we read about the flood of 1342: “On Mary Magdalene’s Day and the following day (July 21/22) an extraordinary cloudburst fell, which swelled the Main River so much that it left its bed everywhere, destroyed fields and vineyards and swept away many houses and their inhabitants. The bridge in Würzburg and the bridges of other towns on the Main were also smashed by the fury of the water. In the city of Würzburg, the river reached the first stone pillar at the Domgreden.”

Highest water level of the Main in Würzburg in 1342

Due to its occurrence on St. Mary Magdalene’s Day, this flood was given the name Mgdalene Flood. At the same time, however, towns and landscapes on the Rhine, Weser, Elbe and Danube were apparently also affected in addition to the area around the Main. Wherever evidence of devastating floods is known, it classifies the damage of July 1342 as the worst known flood disaster of the last thousand years.

One such testimony is the representation of various flood levels of the Main in Würzburg, which can be seen in the following graphic:

The blue scale shows the water level of the Main in centimeters. The average water level is 176 centimeters. With the highest level ever reached of 1000 centimetres, the floods of 21 July 1342 (at the top) exceeded the normal level by more than eight meters – that is almost unimaginable.

Compared with the other recorded flood levels, it is noticeable that all those that have taken place in the last fifty years belong to the group with the lowest values: The most recent example from 2003, for example, shows a level of 648 centimetres – three and a half meters less than the Magdalen flood.

Flood marks in Frankfurt also show the uniqueness of the Marienflut

So-called flood marks, which have been installed in many cities, also serve as a further source of comparison. These show the maximum water levels of certain events with markings on important buildings near the rivers. The next graphic shows such marks on the Iron Footbridge in Frankfurt, a pedestrian bridge over the River Main:

The left-hand image in the graphic shows where the Iron Footbridge is located. The right-hand image shows the flood marks placed there in more detail. Once again, the year 1342 (at the top) stands out: the distance to the next biggest flood of 1682 is around two meters. And here too, the most recent events of 1920 and 1970 are the ones with the lowest flood marks.

The “Great Hunger” from 1315 to 1322

But what was life like for people at the time of the Magdalene Flood? The following explanations are based on information from the book “Kulturgeschichte des Klimas” by Wolfgang Behringer (see here). At the beginning of the 14th century, Europe was struck by an extraordinary famine: the so-called “Great Hunger” from 1315 to 1322. This plague was strongly influenced by abnormal weather conditions: long cold winters shortened the growing season, and persistent rain damaged the harvest.

In the 14th century, these relatively cold and rainy seasons brought a sudden end to the “medieval warm period” from 1000 to 1300, during which the Vikings on Greenland were even able to grow grain and raise livestock. With the onset of the “Little Ice Age”, crop yields were often significantly lower or even completely absent.

Greater risk of erosion due to smaller forest stands

In addition, as a result of a period of relative prosperity in the 13th century, the population grew and economic activity expanded. Because this meant that wood was increasingly in demand as practically the only source of energy, and because more and more arable land was needed, Europe’s forests declined massively: Germany still had around half of its current stock. In the event of severe flooding, however, this loss of forest meant that the soil was less well protected against erosion.

It is assumed that the Magdalene flood alone caused a third of the soil erosion of the last 1500 years: Some villages lost more than half of their arable land. Significant changes to the landscape, such as deep ravines caused by the floods of 1342, are still visible today. Back then, people were plagued by failed harvests, contaminated drinking water sources, hunger and rising prices.

After the flood came the Black Death

And then there was the plague: introduced by the Mongols from China via the Silk Road, this “Black Death” spread from Italy across Europe from 1346 to 1352. And because it hit a population severely weakened by hunger and bad weather, its toll was devastating: in the space of a few years, the population is said to have died by half in many places.

Conclusion: Flood disasters – which have occurred at all times – seem to have tended to be worse in earlier centuries than they are today. And the greatest known catastrophe, the Magdalene Flood, took place at a time when Europe’s climate had cooled and the glaciers had advanced far – in other words, at a time of climate change that is contrary to today’s climate change.