Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
TRENCH
As described in historical dictionaries
Patronymica Britannica (1860)
TRENCH. From La Tranche, a town in Poitou, the possession of the family in eai'ly times. After the massacre of St. Bartholomew, Frederick de la Tranche, or Trenche, a Protestant nobleman, sought refuge from persecution on English ground, and settled in Northumberland in the year 1574. Thence his descendants passed over into Ireland, where they still flourish in the enjoyment of two ijeeragcs, the Earldom of Clancarty, and the Barony of Ashtown.
Surname type: Location or geographical feature
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English