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
Order of battle at Jutland of Jutland. Of these, 28 took part, organized into four Battle Squadrons. The 24 vessels of 2nd, 4th and 1st Battle Squadrons formed the main body of Fleet, and are listed below order from van to rear following their deployment to engage the German fleet, 6:30pm 31 May 1916. 2nd Battle Squadron (Battleships) 1st Division: VAdm Jerram 2nd Division: RAdm Arthur Cavenagh Leveson, C.B. Fleet Flagship (at head of 3rd Division but not part of 4th Battle Squadron) 4th Battle Squadron (Battleships): VAdm Sir Frederick Charles Doveton Sturdee, 1st Baronet, K.C.B., C.V.O., C.M.G.; flag commander: Cdr William Milbourne James 3rd