KERRIGAN Family History
This surname is of Irish origin, and is an Anglicized form of the Old Gaelic "O'Ciaragain", descendant of Ciarogan, a personal byname from a double diminutive of "ciar", black, dark. Traditionally, Irish family names are taken from the heads of tribes, revered elders, or some illustrious warrior, and are usually prefixed by "Mac", son of, or "O", denoting "grandson, male descendant of". The (O)Kerrigan sept belonged to the ancient population group of Hy Fiachrach, and were located in the Connacht ounties of Mayo, Sligo and Roscommon.