Mcnicholas — A Second Son's Name

McNicholas descends from the same Norman de Angulo family as Costello, settled in County Mayo from the thirteenth century. Where one branch took the name Mac Oisdealbhaigh after an ancestor called Oisdealbhach, another took Mac Niocláis, ‘son of Nicholas’, after a different forebear in the same family tree — two Gaelicised surnames from one Norman household.

Two brothers' names, in effect, still answering for the same Norman arrival eight centuries later.

Irish form: Mac Niocláis