Wikipedia
Sétach
Sétach, Gaelic- Irish feminine forename.
The name Sétach is attested in a single entry in the Annals of Ulster, under the year 1042, which records the death of:
- Aedh m. ind abad, .i. m. Mail Muire & Setaige ingine H. Lorcain/Aed son of the abbot i.e. of Mael Muire and of Sétaige daughter of ua Lorcáin.
At least two families bearing this surname are known. One was represented by Dub Sláine ua Lorcáin (d. 1004), abbot of Emly, who was probably first cousin of Brian Boru. A second were kings of Fothairt in Chairn aka Fothart Tíre, in the Barony of Forth, County Wexford.