John Spencer-Churchill, 11th Duke of Marlborough

John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough, DL, JP (13 April 1926 – 16 October 2014) was a British educator. He was the principal of a school in his birthplace of Blenheim Palace.
He was the son of Lt.-Col. John Spencer-Churchill, 10th Duke of Marlborough and his wife, Hon. Alexandra Mary Hilda Cadogan. He was also a relation of The Duke of Devonshire and a generational cousin of the war-time Conservative Prime Minister, Sir Winston Churchill. 
He was also a distant relative of Diana, Princess of Wales as both belong to the Spencer family, and of the Vanderbilt family through his paternal grandmother, Consuelo Vanderbilt.
Spencer-Brown died in the morning of 16 October 2014 in Blenheim Palace, aged 88.