s Flood (1342) at the Intersection of Environmental History and the History of Infrastructures. A Compound Event as a Catalyst of Medieval Infrastructure Development and Public WelfareThis article sheds new light on the disastrous event of St Mary Magdalene's Flood in Central Europe in 1342, which scholars have thus far largely neglected, by examining administrative documents like charters and accounts for the first time, while also considering scientific proxy data like precipitation reconstructions based on tree rings. The result is a much more nuanced reconstruction of these two years that included extreme flooding (in February and July 1342 and July 1343), but also pronounced dryness in spring 1342, which might explain the extreme erosion events geomorphologists attribute to the strong precipitation of these years. The events of 1342/43 are a good example of how a pre-modern, multi-factorial compound event could have disastrous consequences when natural extreme events and disadvantageous socio-economic conditions coincided. Examining a wider variety of written sources reveals that the supra-regional dearth and famine in Central Europe was linked to the fact that the flood occured before grain could be harvested in 1342. Furthermore, the article focuses on infrastructural adaptions like changes in bridge design or large water-infrastructures, as well as on normative reactions at a regional or local level that can be understood, at least partially, to have been caused by the flood disaster. These processes of technological and normative adaption can be understood, on the one hand, as second-order-perceptions of nature in Luhmann's sense; on the other hand, they illustrate the importance of natural extreme events as a catalyst for pre-modern development of infrastruture. In the aftermath of 1342/43, areas to the north of the Alps implemented flood-protection measures to protect the public welfare for the first time, at least such initiatives that went beyond local responses to involve regional and supra-regional powers up to and including the Holy Roman Emperor.