Generally recorded as MacWilliam, McWilliam and McWilliams, this ancient surname is Scottish but of Norman-French origins. It derives from the 11th century Gaelic "Mac Uilleim" meaning the son of William, and it is said that the clan originate from William fitz Duncan, the son of Duncan 11nd of Scotland, and his son Duncan Ban MacWilliam, who was killed at the battle of Man Garvia, in Morayshire in 1187. William was originally a compound personal name of the pre 5th century, consisting of the Germanic and French elements "Wil", meaning will or desire, and "helm", a helmet or protection. It was popular mainly through Duke Willam of Normandy, William 1st of England, who may not have actually introduced it into the British Isles, but who in the spirit of "political correctness", ensured its long term future. It is said that the MacWilliams were powerful claimants for the Scottish throne against King William the Lion (1165 - 1214), since all claimed descent from King Malcolm 111rd of Scotland, 1057 - 1093. The MacWilliam's seem to have lost the arguement as most of their leaders were dead in battle by the year 1215. MacQuilliam and MacKilliam are also current forms of this name, and earlier but now extinct spellings included MacWillzam in 1506, McWilzeme 1527, McWilliame 1548, and M'William 1678. 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.