 It is the name of an Oriel family who were chiefs of Oirtheara, now the baronies of Orier, in the east of County Armagh.According to the traditional Irish pedigree, the family is descended from Slioch Ir, who was the son of Ior and the grandson of Cathal Ruadh, who was killed in 1401.O'Hare is one of the few surnames which resisted the general tendency in the 18th century to discard the 'O' in their name.