Complex sentence: William Cavendish, 2nd Duke of Devonshire (1672--4 June 1729) was a British nobleman and politician, the eldest son of William Cavendish, 1st Duke of Devonshire and Lady Mary Butler.
Split into simpler sentences: William Cavendish, 2nd Duke of Devonshire (1672--4 June 1729) was a British nobleman and politician. He was the eldest son of William Cavendish, 1st Duke of Devonshire and Lady Mary Butler.