Historical Boundries of Denmark

1. Boundary between Prussia and Denmark, 1864-1920.

2. Present Border established in 1920

3. Border along the Eider River dividing Schleswig from Holstein, following very closely the old Danish border from the ninth century.

Note: Before the Danish/Prussian War (1864), the King of Denmark was also the Duke of Holstein with Lauenburg and Duke of Schleswig.