Title: Spencer family
Content: Charles Spencer, 5th Earl of Sunderland, 3rd Duke of Marlborough (1706–1758), general and politician ; George Spencer, 4th Duke of Marlborough (1739–1817), politician ; George Spencer-Churchill, 5th Duke of Marlborough (1766–1840), elder son of the 4th Duke, changed his surname from "Spencer" to "Spencer-Churchill" ; George Spencer-Churchill, 6th Duke of Marlborough (1793–1857), eldest son of the 5th Duke ; John Winston Spencer-Churchill, 7th Duke of Marlborough (1822–1883), eldest son of the 6th Duke (and paternal grandfather of Sir Winston Churchill) ; George Charles Spencer-Churchill, 8th Duke of Marlborough (1844–1892), eldest son of the 7th Duke ; Charles Richard John Spencer-Churchill, 9th Duke of Marlborough (1871–1934), only son of the 8th Duke ; John Albert William Spencer-Churchill, 10th Duke of Marlborough (1897–1972), elder son of the 9th Duke ; John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough (1926-2014), elder son of the 10th Duke ; Charles James Spencer-Churchill, 12th Duke of Marlborough (born 1955), eldest son of the 11th Duke  
Title: Duke of Marlborough (title)
Content:  son of the 6th Duke and paternal grandfather of Winston Churchill ; George Charles Spencer-Churchill, 8th Duke of Marlborough (1844–1892), eldest son of the 7th Duke ; Charles Richard John Spencer-Churchill, 9th Duke of Marlborough (1871–1934), only son of the 8th Duke ; John Albert William Spencer-Churchill, 10th Duke of Marlborough (1897–1972), elder son of the 9th Duke ; John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough (1926–2014), elder son of the 10th Duke ; Charles James Spencer-Churchill, 12th Duke of Marlborough (b. 1955), eldest surviving son of the 11th Duke   The heir apparent to the dukedom is George John Godolphin Spencer-Churchill, Marquess of Blandford (b. 1992), eldest son of the 12th Duke.
Title: John Spencer-Churchill, 11th Duke of Marlborough
Content:  John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough, (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, in Woodstock, Oxfordshire. He was ranked 224th in the Sunday Times Rich List 2004, with an estimated wealth of £185 million. His death was announced on 16 October 2014 by Blenheim Palace.
Title: John Spencer-Churchill, 11th Duke of Marlborough
Content: Justice of the Peace ; Deputy Lieutenant of Oxfordshire 
Title: John Spencer-Churchill, 7th Duke of Marlborough
Content:  John Winston Spencer-Churchill, 7th Duke of Marlborough (2 June 1822 – 4 July 1883), styled Earl of Sunderland from 1822 to 1840 and Marquess of Blandford from 1840 to 1857, was a British Conservative cabinet minister, politician, peer, and nobleman. He was the paternal grandfather of Prime Minister Sir Winston Churchill.
Title: James Spencer-Churchill, 12th Duke of Marlborough
Content:  Charles James Spencer-Churchill, 12th Duke of Marlborough (born 24 November 1955), styled Earl of Sunderland until March 1972 and Marquess of Blandford until October 2014, and often known as Jamie Blandford or Jamie Marlborough, is an English peer and the current Duke of Marlborough. He is the eldest surviving son of the 11th Duke of Marlborough and his first wife, Susan Mary Hornby. As a member of the Spencer family, he is a distant relative of the war-time Conservative Prime Minister Sir Winston Churchill and of Diana, Princess of Wales, born Lady Diana Spencer. He is also a stepbrother of the late Christina Onassis, who was the stepdaughter of Jacqueline Kennedy Onassis, who was once married to U.S. President John F. Kennedy, by the second marriage of his father with Athina Livanos. He is also a descendant of the prominent American Vanderbilt family through his great-grandmother Consuelo Vanderbilt.
Title: John Spencer-Churchill, 7th Duke of Marlborough
Content: George Charles Spencer-Churchill, 8th Duke of Marlborough (13 May 1844 – 9 November 1892), whose son Charles Spencer-Churchill, 9th Duke of Marlborough, married into the Vanderbilt family. ; Lord Frederick John Winston Spencer-Churchill (2 February 1846 – 5 August 1850) ; Lady Cornelia Henrietta Maria Spencer-Churchill (17 September 1847 – Upper Brook Street, Mayfair, London, 22 January 1927), married 25 May 1868 Ivor Bertie Guest, 1st Baron Wimborne, by whom she had issue. ; Lord Randolph Henry Spencer-Churchill (13 February 1849 – 24 January 1895), married 15 April 1874 Jennie Jerome. Their issue included Sir Winston Churchill and John Strange Spencer-Churchill. ; Lady Rosamund Jane Frances Spencer-Churchill (9 November 1851 – 3 December 1920), married 12 July 1877 William 
Title: George Spencer-Churchill, 8th Duke of Marlborough
Content:  Marlborough was born in England on 13 May 1844. He was the eldest son of John Spencer-Churchill, 7th Duke of Marlborough (1822–1883), who served as Lord Lieutenant of Ireland and Lord President of the Council, and Lady Frances Anne Emily Vane (1822–1899). He was the elder brother of Lord Randolph Churchill and the uncle of Winston Churchill. His paternal grandparents were George Spencer-Churchill, 6th Duke of Marlborough, and Lady Jane Stewart, daughter of Admiral George Stewart, 8th Earl of Galloway. His maternal grandparents were Charles Vane, 3rd Marquess of Londonderry and Frances Vane, Marchioness of Londonderry. Like his father before him, he was educated at Eton College, entering in 1857 and being expelled in 1860.
Title: John Spencer-Churchill, 10th Duke of Marlborough
Content:  He was born in London on 18 September 1897 as the first of two sons born to Charles Spencer-Churchill, 9th Duke of Marlborough and his first wife, the former Consuelo Vanderbilt, an American railroad heiress. His younger brother was Lord Ivor Spencer-Churchill who joined the Royal Army Service Corps and fought in the First World War. His parents separated in 1906 and divorced in 1921. Later that year his mother married Lt. Col. Jacques Balsan, a French balloon, aircraft, and hydroplane pilot, and his father married the French American Gladys Deacon. His paternal grandparents were George Spencer-Churchill, 8th Duke of Marlborough and his first wife, Lady Albertha Hamilton (a daughter of James Hamilton, 1st Duke of Abercorn and Lady Louisa Russell). His mother was the eldest child, and only daughter, of William Kissam Vanderbilt, a New York railroad millionaire, and the former Alva Erskine Smith. They divorced in 1895; she married his friend Oliver Belmont and he married the widow Anna Harriman. His maternal uncles were William Kissam Vanderbilt II and Harold Stirling Vanderbilt. Marlborough was educated at Eton before joining the Life Guards.
Title: George Spencer-Churchill, 6th Duke of Marlborough
Content:  George Spencer-Churchill, 6th Duke of Marlborough, DCL (27 December 1793 – 1 July 1857), styled Earl of Sunderland until 1817 and Marquess of Blandford between 1817 and 1840, was a British nobleman, politician, and peer. The great-grandfather of Sir Winston Churchill, he served as Lord-Lieutenant of Oxfordshire between 1842 and 1857.

Question: Who is the father of John Spencer-Churchill, 11th Duke of Marlborough?
Answer: John Spencer-Churchill, 10th Duke of Marlborough.
Marquess of Blandford.
John Albert William Spencer-Churchill, 10th Duke of Marlborough.
John Spencer-Churchill.