This rare and interesting surname is of Irish origin, and has two possible sources; the first source is a variant of (O) Manahan, which is from the Gaelic "O' Mainichin", derived from "manach", a monk. The second source is as a synonym of MacNeice, which is a variant of "MacAonghuis", son of Angus, a Gaelic personal name meaning "one choice". Mannix was a minor sept of Corca Laoidhe in the south-west of County Cork, the name was never numerous and is now scarce, being rarely found outside the counties of south-west Munster. The surname is sometimes Anglicized as Mannihan or Manahan. Surprisingly there are no early recordings of the surname; it does not appear in records until the late 18th Century. Among the sample recordings in Ireland are the marriages of Timothy Mannix and Brigid Murphy on August 25th 1843 at Dromtarriff R.C., County Cork and of John Mannix and Catherine Mannix on November 19th 1843 at Castleisland R.C. County Kerry. The first recorded spelling of the family name is shown to be that of Mary Mannix (christening), which was dated April 23rd 1785, Killarney Roman Catholic Church, County Kerry, Ireland, during the reign of King George 11, "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.