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
Battle of Jutland him west of the mouth of the Skagerrak off the coast of Jutland and wait for the Germans to appear or for their intentions to become clear. The planned position would give him the widest range of responses to likely German moves. The principle of concentration of force was fundamental to the fleet tactics of this time (as in earlier periods). Tactical doctrine called for a fleet approaching battle to be in a compact formation of parallel columns, allowing relatively easy manoeuvring, and giving shortened sight lines within the formation, which simplified the passing of the signals necessary for command