John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough, JP, DL (13 April 1926 – 16 October 2014) was a British peer. He was the elder son of the 10th Duke of Marlborough and his wife, the Hon. Alexandra Mary Hilda Cadogan. He was known as "Sunny" after his courtesy title of Earl of Sunderland.
His principal seat was Blenheim Palace, Woodstock, Oxfordshire. He was ranked 224th in the Sunday Times Rich List 2004, with an estimated wealth of £185 million.
He was educated at Eton College and served seven years in the Life Guards, in which he achieved the rank of captain. In 1972, on inheriting the Dukedom of Marlborough, he assumed the management of Blenheim Palace and the Blenheim estate.
To fund the maintenance of the house, he opened it to visitors and as a film set, and established a number of businesses, including a garden furniture company and a water bottling plant.[1]
He was also active in a range of organisations, including the Thames and Chilterns Tourist Board and Oxford United Football Club. He served as vice-president of the Witney Conservative Association, the local party of David Cameron.
He died in 2014 at the age of 88.[2]
Marlborough was married four times and had a total of six children, two of whom died in infancy.[citation needed]
Firstly, he married Susan Mary Hornby (1929–2005), daughter of Michael Charles St John Hornby and Nicolette Joan Ward, on 19 October 1951.[3] They divorced in 1961 after having three children:
Secondly, on 23 October 1961, he married Athina Onassis (née Livanos), former wife of Aristotle Onassis, and daughter of Stavros Livanos. They were divorced in March 1971 and had no children.[citation needed]
Thirdly, on 20 May 1972, he married Countess Rosita Douglas-Stjernorp, daughter of ambassador Count Carl Douglas-Stjernorp and Ottora Haas-Heye. They had three children and were divorced in 2008.[4]
Finally, at the age of 82, Marlborough married Lily Mahtani (née Sahni; born c. 1954–57 in Iran) 3 December 2008 in the Private Chapel at Blenheim.[7] There were no children from this marriage.