Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
SARSFIELD
As described in historical dictionaries
Patronymica Britannica (1860)
SARSFIELD. The first of the family of Sarsfield who settled in Ireland, is said to have been Thomas de S., " chief bannerbearer" to King Henry IL, A.D. 1172. The name is unquestionably English, and local.
Surname type: Location or geographical feature
Origin: Celtic
Region of origin: British Isles
Country of origin: Ireland
Religion of origin: Christian
Language of origin: Gaelic