Galbraith
Galbraith—This name is the representative of an ancient Strathclyde sept of Picto-Cymric origin, who afterwards became powerful in the Lennox country, in Stirling County, where they held the lands and castles of Craig Maddier, Gartconnell, and Culcruich. They were commissioned to hunt the Clan McGregor in the reign of James VI., and later they were outlawed themselves on the advice of the Earl of Argyle, thus the two clans sharing the same severity, and they, like the McGregors, were not allowed to use their own name, hence we read of similar tyrannical laws against the clan Lamond. The name was written Galbreit in the Lennox in the 13th century. The name is common in Perthshire, and its Gaelic form is Mac A' Bhreatnaich.
The meaning of the name is the "Stranger Briton," and its other form, McBratney (Mac A' Bhreatnaich) which means the "Son of the Briton or Welshman." In Galloway the name is written McBratney and McBretney.