Recorded in an amazing range of spellings including Macilriach, Macilraith, McIlwraith, McIlwrath, Macgillreich, Macilwrick, Macillrick, Macilurick and many others, this is a derivation from the pre 10th century Scottish Gaelic "Mac gille Riabhaich". The name literally translates as "The son of the follower of the brindled one", and was a nickname reference to an original chief of the clan who may well have been Norse or even Saxon. The surname is widespread in Galloway and throughout the original kingdom of Strathclyde up the west of Scotland. Examples of early recordings abound although it is difficult to rationalise the spelling as all belonging to the same clan! They include examples such as Thomas M'Gilrewy, a tenant of the Clan Douglas in the barony of Buittle in 1376; Duncan McGillereach of Fandownyach, in 1503, and Nele M'Ilwrath, a follower of the earl of Cassilis, who was respited (charged) with murder in 1526. In Kilmuir, Isle of Skye, there is a place called Baile Mhic Illeriabhaich or the place of the Macilwraiths. A bond of manrent was signed between them and MacDonald, lord of the Isles, at Castle Camus, Skye, on August 13th 1632. Possibly the first recorded spelling of the family name is of Andrew makgille Reuth, as spelt and dated 1300. He died at Carlisle Castle, where he was apparently held as a prisoner of the English. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.