Which British peer and politician born in 1734 was a great-grandson of the 1st Duke of Marlborough?
John Spencer, 1st Earl Spencer John Spencer, 1st Earl Spencer (19 December 1734 – 31 October 1783) was a British peer and politician.
William Cavendish, 1st Duke of Devonshire William Cavendish, 1st Duke of Devonshire (25 January 1640 – 18 August 1707) was an English soldier, nobleman, and Whig politician who sat in the House of Commons from 1661 to 1684 when he inherited his father's peerage as Earl of Devonshire. He was part of the "Immortal Seven" group that invited William III, Prince of Orange to depose James II of England as monarch during the Glorious Revolution, and was rewarded with the elevation to Duke of Devonshire in 1694.