Complex sentence: Born around 1627, Brouncker was the second son of William Brouncker, 1st Viscount Brouncker and Winifred Leigh; and the younger brother of William Brouncker, 2nd Viscount Brouncker, who was President of the Royal Society, and a well-known mathematician.
Split into simpler sentences: Born around 1627, Brouncker was the second son of William Brouncker, 1st Viscount Brouncker and Winifred Leigh. He was the younger brother of William Brouncker, 2nd Viscount Brouncker, who was President of the Royal Society, and a well-known mathematician.