Das Wärmeoptimum des Hochmittelalters. Beobachtungen zur Klima- und Agrarent-wicklung des Hoch- und Spätmittelalters.

The article discusses climatological research into the relation of climate and agrarian rents during the High and Late Middle Ages in Europe. The period of warming from the 11th to the 13th century is described, which some have related to the blooming of European culture, the Crusades, population growth, an agrarian revolution, and the construction of the great European cathedrals. Later historians' expressions of skepticism about these conclusions are reviewed. The historiography and climatological research methods of scholars in the dispute are reviewed.