This interesting surname of Irish origin is an Anglicized form of the Gaelic "O'Mainnin" meaning descendant of Mainnin. The sept was located in the barony of Tiaquin, Co. Galway, their chief residence being the castle of Clogher. They were an important sept in the Hy Many country, but were not of that group by descent, as their ancestors were the ancient pre-Gaelic Pictish rulers of that area. Their territory was much reduced by the O'Kelly's, and their estates were largely lost in the 17th Century confiscations, but the O'Mannions remained in their homeland where they are numerous today. The name has also been Anglicized Manning. Cornet John Manning of O'Neills Dragoons in King James 11's Irish Army was an O'Mannin. Church Records list the marriage of Denis Manion to Sarah McDermus on August 13th 1792 at the Cathedral, Manchester, and the christening of Edward Mannion on March 6th 1836 at St. Mary's, Lambeth, London. One Michael Mannion, aged 32 yrs., together with his wife Mary, aged 28 yrs, who were famine emigrants, sailed from Galway aboard the "Clarence" bound for New York on May 19th 1846. The first recorded spelling of the family name is shown to be that of John Manyon, which was dated November 1st 1619, marriage to Ann Eastway, at St. Margaret's, Westminster, London, during the reign of King James 1st of England and V1 of Scotland, 1603 - 1625. 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.