“The geneticist Daniel Bradley and his colleagues identified a Y-chromosome type that is present in two to three million people today and derives from an ancestor who lived around fifteen hundred years ago.16 It is especially common in people with the last name O’Donnell, who descend from one of the most powerful royal families of medieval Ireland, the “Descendants of Niall” – referring to Niall of the Nine Hostages, a legendary warlord from the earliest period of medieval Irish history.”
