In Irish the surname is O hEigceartaigh, from eigceartach, meaning "unjust". The name appears to have arisen first in the area now divided between counties Derry and Donegal, where the O hEigceartaigh were a branch of the Cinel Eoghain, that large group of families claiming descent from Eoghan, one of the sons of Niall of the Nine Hostages, the fifth century monarch who supposedly kidnapped St. Patrick to Ireland. However, today the surname is much more common in Co. Cork, at the other end of the country. Traditionally, the Cork (O')Hegartys were claimed as a branch of the more historically prominent northern family, but ecertach was a common personal name in Munster, and it seems more likely that the surname arose separately there. At any rate, O'Hegartys are recorded in west Cork as early as the thirteenth century, and remain strongly associated with the area.