Athelstan (or Ã†thelstan) (Old English: Ã†Ã¾elstan, Ã†Ã°elstÄn) (c. 893 / 894 â€“ 27 October 939), called the Glorious, was the King of England from 924 or 925 to 939. He was the son of King Edward the Elder, and nephew of Ã†thelflÃ¦d of Mercia. Ã†thelstan's success in securing the submission of Constantine II, King of Scots, at the Treaty of Eamont Bridge in 927 through to the Battle of Brunanburh in 937 led to his claiming the title "king of all Britain". His reign is frequently overlooked, with much focus going to Alfred the Great before him, and Edmund after. However, it was of fundamental importance to political developments in the 10th century. Athelstan was the first King of a unified England from 927 A.D.