Of the Eóganachta, eighth from Fínghin, king of Munster ca. 600 AD, was Eochaid, who assumed the nickname, Súilleabháin, meaning ‘dark-eyed' or 'one-eyed', whence come the Ó Súilleabháin, Princes of Munster. Of the septs, the Ó Súilleabháin Mór were most senior.
Ancient Territory: With the loss of their ancient lands at Knockgraffon in the Norman era, the Ó Súilleabháin retreated to Desmond. For a long while the seat of the Ó Súilleabháin Mór was Dunkerron castle in southern Kerry.