Ó Catháin is an Irish surname meaning "descendant of Cathán.” The root name Cathán derives from Old Irish cath “battle” combined with a diminutive suffix, thus meaning “little battle.” Saint Cathán was a 6th-century Irish monk and missionary to the Isle of Bute.Historical SeptThe O'Cahans were a powerful sept of the Northern Uí Néill's Cenél nEógain in medieval Ireland. They originated in Laggan (east County Donegal) and moved eastwards in the 12th century, ousting the O'Connors from Keenaght in present-day County Londonderry. They held the lordship of Keenaght and Coleraine until the 17th century, a territory often called "O'Cahan's country." Subordinate to their kin, the O'Neills, the O'Cahans held the privilege of inaugurating the O'Neill chief by tossing a shoe over his head in acceptance of rule.A separate, unrelated sept, the Ó Catháin Uí Fhiachrach, existed in Connacht.Anglicized FormsThe surname is commonly anglicized as Kane, Kean, Keane, or O'Kane.Meaning: Descendant of Cathán (little battle)Origin: Irish (Gaelic)Type: Surname (patronymic)Usage Regions: Ireland, especially Ulster (Derry, Donegal)