“Muintir Neachtain.—The family name is O’Neachtain, and is now anglicised Naghten, and sometimes corrupted Norton. The family were afterwards probably in the time of Conor Moenmoy O’Conor, removed from Moenmagh to the Feadha, or Fews, of Athlone, in the barony of Athlone, in the county of Roscommon, where Shane O’Naghten was chief of the sept in the reign of Elizabeth, and where E. H. Naghten, Esq., of Thomastown Park, the present head of the O’Naghtens, enjoys a very considerable remnant of the territory of his ancestors.”
From The Tribes and Customs of Hy-Many, commonly called O’Kelly’s Country (Author: Unknown), p.68 (section .2)