Treaty of Heiligen

The Treaty of Heiligen was signed at Heiligen in 811 between the Danish King Hemming and Charlemagne. Based on the terms of the accord, the southern boundary of Denmark was established at the Eider River. Moreover, the treaty confirmed the peace established by both signatories in 810.

Since the days of King Offa the Eider river had been the border between the settlement area of the Angles and Saxons. After Charlemagne had subjected the Duchy of Saxony to his rule, Hemming's predecessor and uncle Gudfred took the chance, crossed the Eider and campaigned the southern lands, which Charles had left to the allied Obotrites. The king however was killed by his retinue in 808 and Hemming, to assure his rule against his rivaling cousins, sought peace with the Franks. His and the Emperor's negotiators met on an island of the Eider in present-day Rendsburg and defined the limits of their spheres of influence.

Though in the following decades several quarrels occurred in the border area and the German King Henry I conquered Danish Hedeby at the Danevirke in 934, the border was confirmed by Canute the Great and King Conrad II in 1025 at the betrothal of their children Gunhilda and Henry III. For centuries the Eider marked the border between the (South Jutland) Duchy of Schleswig and Holstein in the Holy Roman Empire resp. the German Confederation. The Duchy of Schleswig-Holstein was ruled by one duke and was not to be split up, the duke had become King of Denmark as well. In the Second Schleswig War of 1864 Prussian and Austrian troops crossed the river and annexed Schleswig.

Sources

• Thursten, Tina L. (2001). Landscapes of Power, Landscapes of Conflict: State Formation in the South Scandinavian Iron Age. New York: Kluwer Academic. p. 340. ISBN 030644979X. 

External links

• Denmark, Kings
• History of Denmark
• A Brief History of Denmark