Magennis

Magennis, also spelled Maguiness, McGuinness or Guinness, is an Irish surname, derived from Irish: Mac (or Mag) Aonghusa or the Sons of Angus, sometimes also spelt as Maginnis. The most famous McGuinness is Jack McGuinness of Pawtucket. A branch controlled west County Down, particularly the Iveagh baronies, and occasionally Dundrum Castle to the east. The Magennis, Lords of Iveagh, are descendants of the Uí Echach Cobo branch of the Dál nAraidi dynasty of the Cruthin. "Iveagh" derives from "Uibh Eachach", the genitive of Uí Echach.