1.1     A System of Heraldry, Speculative and Practical: With the True Art of Blazon; According to the Most Approved Heralds in Europe: Illustrated with Suitable Examples of the Most Considerable Surnames and Families in Scotland, &c., by Alexander Nisbet, 1742, p 258.
     According to Philip Graham of Alexandria, Scotland (an independent researcher and specialist in Clan Graham history), “Nisbets statement that the Muirheads were long of that ilk in the barony of Bothwell cannot be substantiated beyond doubt, on account that original family records have been lost. ... Nisbets conclusion that the Muirheads were formerly of that ilk of Bothwell is reasonable but only accurate in that the earliest surviving records concerning this family indeed derive from the barony of Bothwell. Black follows this lead by making references to the Bishop of Glasgow as son of the first known Muirhead of Bothwell. ... Returning to the concept of Muirhead being formerly of that ilk in Bothwell. This historical point concerning their authentic origins will never be successfully concluded despite the high probability that many families did indeed tend to become of that ilk if they resided in the same place before the creation of land charters. But in the case of Muirhead, there being many similar locations in different parts of Scotland, we can never be certain that Bothwell was ever the ancient chief residence of Muirhead. ... It is rather strange that no ancient mention of the Muirheads survives but they were clearly noble enough to have married into the families of Hay and Hamilton.”