Irish Female Family Names

Female Gaelic surnames differ from male surnames because girls & women could not be a son or grandson! Accordingly, Ó (from Ua meaning grandson of) is replaced with Ní and Mac (meaning son of) is replaced with Nic. These are contractions of the original form of the female surnames "Iníon Uí" and "Iníon Mhic" (modern O and Mac). The naming system worked like this

The forename is placed first and is followed by "Iníon Uí" which in turn is followed by her great Grandfathers name for example -Iníon Uí Donaill - meaning daughter of the grandson of Donal. Where Mac is used the original form was "Iníon Mhic" meaning the daughter of the son of (name) for example Máire Iníon Mhic Donaill translates as Mary daughter of the son of Donal

When women married they dropped the ní and nic and took the title "Bean" (p. ban) meaning wife for example Bean Uí Dhónaill or Bean Mhic Gearailt.

Obviously surnames could change with each generation but there is evidence to suggest that surnames were becoming fixed (like those of today) before the Norman Invasion. According to Fr. Woulfe, an early authority on Irish surnames, the first recorded fixed surname is O'Clery (Ó Cleirigh), as noted by the Annals, which record the death of Tigherneach Ua Cleirigh, lord of Aidhne in Co. Galway in the year 916. It seems likely that this is the oldest surname recorded anywhere in Europe.