Roark Irish: reduced variant spelling of O’Rourke.
O'Rourke: very numerous in all areas of Ireland, least in Cork. From Irish Ó Ruairc (perhaps "red hero"). With O'Reilly, the other leading sept of Breifne (Cavan-Leitrim). After the destruction of the Gaelic polity in the 17th Century, they achieved distinction in Europe, particularly in Austria and Russia.