This ancient and distinguished surname is of early medieval Irish origin, and is an Anglicized form of the Old Gaelic "O'Miadhachain", descendant of Miadhachain, a male given name meaning "Honourable". Traditionally, Irish family names are taken from the heads of tribes, revered elders, or some illustrious warrior, and are usually prefixed by "O", grandson, male descendant of, or "Mac", denoting "son of". The main (O)Meehan sept was a branch of the illustrious MacCarthys of Munster, but by the end of the 11th Century, the family had migrated and established themselves in the Connacht county of Leitrim, where Ballaghmeehin, or Ballymeighan, in the parish of Rossinber, County Leitrim, locates them. From here, the sept spread into the adjacent counties of Sligo, Fermanagh and Clare. The modern surname has several spelling including Meenehan, Meighan and Meehan. Thomas and Denis O'Meehan were successively bishop of Achonry, County Sligo, between 1251 and 1285, and from early times the (O)Meehans were erenaghs of Devenish, County Fermanagh, that is, holders of church property from generation to generation. The family also preserved a manuscript of the 6th Century St. Molaise of Devenish for over a thousand years: the document is now in the National Museum of Ireland. In 1317, the (O)Meehans were mentioned as one of the County Clare septs associated with the O'Briens. Rev. Charles Patrick Meehan (1812 - 1890) was a distinguished ecclesiastic and historian. The first recorded spelling of the family name is shown to be that of Edru O'Meighan, which was dated 1152, in the "Early Ecclesiastical Records of Kells", County Meath, during the reign of Turlough Mor O'Conor, High King of Ireland, 1119 - 1156. 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.