Ó Muircheartaigh
Ó MUIRCHEARTAIGH—I—O Morierty, O Murtagh, Moriarty, Murtagh, Murtaugh; 'descendant of Muircheartach' (sea-director, expert navigator); the name (1) of a Kerry family who were anciently chiefs of Aos Aisde, a district lying probably along the river Mang; and (2) of a Meath family still numerous in that county and in Monaghan, where it is anglicised Murtagh. In Munster it is always anglicised Moriarty.
Alphabetical Index to Irish Surnames