Adolphus VIII, Count of Holstein (b. 1401)
Adolphus XI of Schauenburg (Low German: Alef or Alv, German: Adolf von Schauenburg, Danish: Adolf 8. af Holsten-Rendsborg) (1401 – 4 December 1459), as Adolph I Duke of Schleswig (Danish: Sønderjylland, formerly Slesvig), and as Adolph VIII Count of Holstein-Rendsburg, was the mightiest vassal of the Danish realm.