This interesting name is of Medieval Irish origin and is the Anglicized modern form of 'O' hAileagain', meaning a descendant of 'Aileagan' a personal name from a diminutive of 'aille', beauty. Halligan is an Oriel sept of Louth and Armagh, found there as early as 1042. It is also written as 'O' hAllagain', and was found as O' Hallagan, and O' Hollegan in North Connacht in the 16th Century, as it is today, and as Olligan in County Kildare in modern times. Amongst the sample recordings in Ireland is the christening of Margarett Halligan, the daughter of Turlagh Halligan, on February 14th 1655 at Derry Cathedral, Templemore, Londonderry, and the birth of James Halligan on May 24th 1864 at Monasterboice, County Louth. The first recorded spelling of the family name is shown to be that of William O' Halegan, which was dated 1597, in County Kildare, during the reign of Queen Elizabeth 1, known as 'Good Queen Bess', 1558 - 1603. 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.