Perhaps answer may be found in the ancestral tree of the present Rt. Hon. Kenneth Randolph Murray, 11th Earl of Dunmore. I know that the Adairs had some lands in Dunmore, probably through the marriage of Janet Dunbar. They may have already had some there. The 1st Earl of Murray may have been Sir Thomas Randolph whose mother was sister of King Robert of Scotland. Sir Thomas was Regent of the King of Scotland (a young lad). Sir Thomas's dau. was "Black" Agnes Dunbar of Dunbar Castle (see seige of Dunbar 1338). A Patrick Dunbar, Earl of March had 1/2 barony of Tibres & Morton in Dumphriesshire in 1363.