Original: William Cavendish, 4th Duke of Devonshire, KG, PC (8 May 1720   2 October 1764), styled Lord Cavendish before 1729 and Marquess of Hartington between 1729 and 1755, was a British Whig statesman who was briefly titular Prime Minister of Great Britain.
Simplified: William Cavendish, 4th Duke of Devonshire, KG, PC (1720 - 2 October 1764) was a British Whig statesman who was Prime Minister of Great Britain for a short period of time.