This interesting name is of Irish origins and appeared with the Prefix "O" until the 17th Century. In the 16th and 17th Centuries references are plentiful but by 1550 the sept had been dispersed from their homeland in Connacht, and seem to be found subsequently in counties Limerick, Kildare, Offaly and Tipperary. The derivation of this name is almost certainly from the Gaelic "Gruagain", a personal name from a diminutive of "gruag", hair, but Grogan may also be the Anglicization of the Gaelic "Grugain" from the personal name "Grugan", a diminutive of grug, fierceness. In the Tudor Fiants the name is usually recorded as O' Grogan but also with variants such as O'Grogane, O'Growgane, and O'Gruogan. One Nathaniel Grogan (1740 -1807), a painter of note, was a Cork man. The first recorded spelling of the family name is shown to be that of Maelbrighde O' Grugain, of Elphin, which was dated 1265, in the "Annals of the Four Masters", self styled king of Ireland, during the reign of De Brugo, (a Norman Conqueror), 1260 - 1265. 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.