MOLYNEUX. 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 (1593-1636) 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, etc. 1698) created much stir at the time. The latter's son Samuel Molyneux (1689-1728), was also a well-known astronomer.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)