This historic English name came into the country from France at the time of the Norman Conquest through William de Molines (Moleyns, Molyneux), who obtained a grant of Sefton, in Lancashire, whence come the earls of Sefton to -day. His descendant Adam de Molyneux (Moleyns or Molins), who died in 1450, was bishop of Chichester and keeper of the privy seal; he was a son of Sir Richard Molyneux of Sefton, and uncle of the Sir Richard Molyneux (d. 1459), the Lancastrian and favourite of Henry VI., whose descendant Richard Molyneux (1J93-1636) was created in 1628 1st Viscount Molyneux of Maryborough, a title now merged in that of Sefton (created 1771). Another Molyneux family of some importance is the Irish one, descended from Sir Thomas Molyneux (1531-1597), Irish chancellor of the exchequer, who, born at Calais, settled in Ireland in 1576. He was the great-grandfather of Sir Thomas Molyneux, Bart. (1661-1733), a well-known physician and zoologist, and of William Molyneux (1656-1698), the philosopher, astronomer and politician, the friend of Locke, and author of Dioptrica nova (1692), whose famous work on the legislative independence of Ireland (The Case of Ireland, &c. 1698) created much stir at the time. The latter's son Samuel Molyneux (1689-1728), was also a well-known astronomer.