The Ice-Regime of the Danube and Winter Crossing Over Rivers in the Early Modern Times (1529–1650)

The aim of this paper is to show the potential of study of private correspondence both in the reconstruction of past weather and climate on the one hand, and on the other in presenting some elements of the ice-regime of the Danube in the early modern period with its possible historical climate implications. The paper shows the results of the study of more than 10,000 private letters from the period between 1529 and 1650. The investigation resulted in dozens of previously unknown mentions of the presence of ice in the upper section of the Danube in the Carpathian Basin. Based upon this, it is possible to show some extremely cold or lasting winters and also to derive some general characteristics of the winters of the period. The paper shows that it is likely that the Danube froze over more frequently in the early modern period than it has done in the modern (instrumental) period which, amongst other reasons (human intervention in particular), could be attributable to change in the natural climatic conditions. Overall, the 120 years studied are considered a characteristically cold period of the Little Ice Age and it may be of primary importance to demonstrate similar climatic trends in the fluctuation of winter average temperatures in the Carpathian Basin and neighboring territories (Austria, Bohemia, Bavaria, and so forth). Apart from showing the potential of the study of the ice regime of rivers in reconstructing the past winter climates of the Carpathian Basin, the paper shows the need for the study of under-investigated types of evidence to gain historical environmental data.