Jutland peninsula is made up of the German Bundesland of Schleswig-Holstein. Schleswig-Holstein has two parts: the former duchies of Schleswig (Danish fief) and Holstein (German fief), both of which have passed back and forth between Danish and German rulers several times. The last adjustment of the Danish–German border followed the Schleswig Plebiscites in 1920 and resulted in Denmark's regaining Northern Schleswig ( or more commonly today: "Sønderjylland"). The historical southern border of Jutland are areas south of Kiel, Husum and Rendsburg, but the river Eider was the border between the former duchies of Schleswig and Holstein, as well as the historical
Jutland border between the Danish and German realms from c. 850 to 1864. Although most of Schleswig-Holstein is geographically part of the Jutland peninsula, most German residents there would not identify themselves with Jutland or even as "Jutlanders", but rather with "North Germany" () and Schleswig-Holstein, considering themselves "Northern Germans" () and "Schleswig-Holsteiner". The medieval law Code of Jutland applied to Schleswig until 1900 when it was replaced by the Prussian Civil Code. Some rarely used clauses of the Jutlandic Code still apply north of the Eider, even some cities south of the river- all of Rendsburg and more than half