Sir John William Fortescue KCVO FRHistS (28 December 1859 – 22 October 1933)[1] was a British military historian.

He was a historian of the British Army and served as Royal Librarian and Archivist at Windsor Castle from 1905 until 1926.

[3] Fortescue was educated at Harrow School and Trinity College, Cambridge, later lecturing at Oxford (DLitt (Oxon)).

[1][4] Fortescue is best known for his major work on the history of the British Army, which he wrote between 1899 and 1930.

[6] He served as president of the Royal Historical Society from 1921 to 1925[7] and was elected an honorary fellow of Trinity College, Cambridge.