William Brouncker, 2nd Viscount Brouncker

William Brouncker, 2nd Viscount Brouncker (about 1620 to 1684), was an Anglo-Irish peer and mathematician who served as president of the Royal Society from 1662 to 1677 and is best known for introducing Brouncker's formula. Born at Castlelyons in County Cork as the elder son of the first viscount, he obtained a DM at the University of Oxford in 1647 and, as a staunch Royalist, lived quietly and devoted himself to mathematical studies until 1660. He was one of the founders and the first president of the Royal Society, became chancellor to Queen Catherine in 1662 and was appointed a commissioner of the Royal Navy in 1664, a career that can be traced in the diary of Samuel Pepys, who on the whole respected him more than most of his colleagues. He was deprived of the presidency in 1677, was commissioner for executing the office of Lord High Admiral of England from 1679, never married and left most of his property to the actress Abigail Williams, with whom he lived for many years.