This name is the Anglicized version of the Scottish-Gaelic name "M' Glaisein", a diminutive form of "M' Ghille ghlais", which means the son of the grey lad, "glas", being the Gaelic word for grey, green and blue. The surname first appears in records at the beginning of the 16th Century. Iain Mc Glassan or McGlassane was a witness at Ardgartene (Highland Papers, 1515). John McGlassan witnessed an instrument of Sasine (act of given legal possession of property) in the Lamont papers in 1519. Several MacGlasham who settled in the lowland are said to have Anglicized their name into Gray. The name also exists in the form Glashen, and MacGilleglas in Scotland. The surname is found also in Ireland as "Mac Glasain", which can be Anglicized as "Greene", widespread in Ulster, probably introduced during the Ulster Plantation in the 16th Century. The earliest recording of the surname in London dates from June 17th 1770 at St. Marylebone church, London when Elizabeth, daughter of William and Elizabeth McGlashan was christened. The first recorded spelling of the family name is shown to be that of Mulmory M'Glassen, which was dated 1500, "A Genealogical deduction of the family of Rose of Kilravock", during the reign of King James 1V, "Ruler of Scotland", 1488 - 1513. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.