Breathnach

Breathnach or Bhreathnach (meaning Welshman) is an Irish surname, indicating a person of Welsh descent. It is the Irish-language version of surnames such as Brannagh, Brunnock, Brannick, Walsh, Wallace, and Wallis.

However, it does not necessarily mean that the ancestor concerned was from modern-day Wales; Robert Bell notes that Wallace was a surname indicating a Irish native of Strathclyde or any part of the Latin name Wallensis meant just that. The name appears in twelfth-century records of Ayrshire and Renfrewshire, parts of the old Strathclyde kingdom ... Wallace has also been used as a synom of Walsh." (Bell, p.244). The best known bearer of the name from the area was Uilleam Breatnach (William Wallace).