Multi-methodological reconstruction of the lake level at Morgarten in the context of the history of the Swiss Confederation

Abstract

In AD 1315, the Habsburgs fought against the Swiss Confederation at Morgarten. Since historical records are very limited, the battle has been the subject of very controversial discussions. Its location and outcome seem likely to have been influenced by the landscape and the size of the Aegeri lake, but only sparse and contradictory information are available. Numerical, semi-quantitative and relative dating techniques were applied to reconstruct the lake’s dimensions and the landscape. Results obtained from radiocarbon dating of mires (last sedimentation phase of the lake), geomorphic mapping, geoelectrics, soil maps (surface age indication) and archaeological findings were pieced together and gave an astonishingly good consensus. In the Lateglacial, the lake level was higher (750–760 m a.s.l.): because of a catastrophic event, it decreased by 25 m. About 5500 BP, the lake level was at 732 m a.s.l., and since the Roman period, it has varied between 724 and 727 m a.s.l. At the time of the battle the lake was at 726 m – that is, about 2 m higher than today. Together with the cooler climate, the greater extension of the fens and larger lake, the valley floor was wet and unpleasant. If a Habsburg army had to cross this region, they would likely have preferred to walk on a more accessible trail along the footslopes (where they probably were attacked). Precise landscape reconstruction provides new input for historical research. Details about the exact location of the battle, however, remain unclear, and the myth of the battle at Morgarten persists.