History of the Clan
The surname O’Sullivan or in Irish Ó Súilleabháin traces its origin from Míl Espáine or Milisius, King of the Milesians (or Celts), King of Spain through the line of his son, Heber, first absolute King of Ireland 504 BC. The surname O’Sullivan is derived from the words Súil (eye) and abháin, (one) and in its Irish form Ó Súillabháin means descendant of the one eyed or descendant of the hawk-eyed. The O’Sullivans were descendants of Eoghan (Owen) Mór, the father of the famous Olioll Olum, celebrated King of Munster in the third Century. Olioll Olum had three sons, Eoghan, Cormac Cais and Cian, and by his will he commanded that the kingdom should be ruled alternately by one of the descendants of Eoghan and Cormac Cais. From Eoghan, the eldest son of Olioll Olum, descended the Eoganachts or Eugenians, who were styled Kings of Cashel. The Eoghanachts possessed Desmond or south Munster, the present counties of Cork and Kerry; they also held most of the present county of Tipperary. The O’Sullivans were one of the principal families of the race of Eogan or Eoghanacht (i.e. descendants of Eoghan) of Munster.....Read more
