This interesting surname is of Irish origin, and is an Anglicized form of the Gaelic "MacComhdhain", which is composed of the element "Mac", son of, and the personal name "Comhghan", twin. Traditionally, Irish family names are taken from the heads of tribes, revered elders of from some illustrious warrior, and are usually prefixed by "O", grandson, male descendant, or "M(a)c", denoting "son of". In Ulster the name is very numerous in County Armagh as evidenced by the Hearth Money Rolls of the 17th Century. There was evidently also a sept of south Kilkenny and Waterford whose name was Anglicized O'Cowan. In 1582, John Cowas was Chancellor of Christ Church, Waterford. In the modern idiom the surname has many variant spellings ranging from Coen, Cowan and Coan, to Kowen, Keown and Coyne. Recordings of the surname from London Church Registers include: the marriage of Katherine Coan and Richard Morris on September 17th 1693, at St. Katherine by the Tower, and the christening of Robert, son of William and Hannah Coan, at St. Dunstan's, Stepney, on September 18th 1722. On April 3rd 1847, Margaret, aged 60 yrs., Patrick, aged 18 yrs., John, aged 17 yrs., and Mary Coan, aged 19 yrs., famine emigrants, arrived at the Port of New York aboard the "Burlington", from Liverpool. James C MacCoan (1829 - 1903) was a political and historical writer in County Tyrone. The first recorded spelling of the family name is shown to be that of Walter O'Cown, which was dated 1305, in the "Ancient Records of Ireland", during the reign of King Edward 1 of England, known as "The Hammer of the Scots", 1272 - 1307. 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.