 They are said to be descendants of the ancient Irish King Heremon, who, along with his brother Herber, conquered Ireland.Heremon slew his brother shortly after their invasion, took the throne for himself, and fathered a line of kings of Ireland that include Malachi II, and King Niall of the Nine Hostages.Baptismal records, parish records, ancient land grants, the Annals of the Four Masters, and books by O'Hart, McLysaght, and O'Brien were all used in researching the history of the Mooney family name.