Lanigan is an anglicized form of the Olde Gaelic O Lonagain. The Gaelic prefix 'O' indicates 'male descendant of', plus the personal byname Lonagain, believed to derive from 'Ionigh', a verb meaning 'supply' or 'provide'; hence, 'descendant(s) of the supplier'. The original territory of the O' Lonagains lay in Urmhumhan, a ancient land division comprising much of the modern County Kilkenny and North Tipperary. Ballylanigan, situated near Callan, County Kilkenny, derives its name from this clan, the first element coming from the Gaelic 'baile', a town or settlement. In Petty's census of Ireland taken in 1659 the name Lanigan was still most widespread in its original homeland. Doctor John Lanigan (1758 - 1828) was the author of an Ecclesiastical History or Ireland. On July 10th 1866 the birth of one, Thomas Lanigan was recorded in Callan, County Kilkenny. The first recorded spelling of the family name is shown to be that of O' Lonagain of Urmhumhan, which was dated 1297, a list of outlaws in that territory, during the reign of King Edward I of England, 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.