This is an anglicized form of the Olde Gaelic O Glaimhin. The Gaelic prefix "O" indicates "male descendant of", plus the personal byname Glaimhin meaning "Plunderer"; hence, "Descendant(s) of the Rapacious one". This sept originated in Connacht. One branch, belonging to the ancient population group Ui Fiachrach Muaide, was located in north Mayo and Sligo, and the other branch (Aidhne), Occupied south Galway. However, the name Glavin, with variant spellings Glaveen and Glavan is most widespread today in the Munster Counties of Kerry, Cork and Waterford. On April 23rd 1793 Bridget Glavin and Patrick Leahy were married in Tallow, Co. Waterford, and on July 18th of that year Margaret Glavan, an infant was christened in Killarney, Co. Kerry. The name appears in early 13th Century London church registers. On June 26th 1831 Patrick Glavin and Catherine Sullivan were married in St. Anne Soho, Westminster and on January 5th 1841 Denis Glavin married a Winnifred Clearey in St. Pancras, Old Church, London. The first recorded spelling of the family name is shown to be that of Elizabeth Glaveen, daughter of John Glaveen, which was dated christened in Killarney, Co. Kerry, during the reign of King George III, "Farmer George", 1760 - 1820. 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.