Recorded in several spellings as shown below, this surname is of early medieval Irish origin. It derives from the Gaelic O' Miadhachain, meaning the male descendant of the son of the honourable one! Traditionally, Gaelic family names are taken from the heads of tribes, and were usually prefixed by O' in Ireland, and sometimes Mac, the latter 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, they had migrated to County Leitrim, at Ballaghmeehin in the parish of Rossinber. From there they spread into the adjacent counties of Sligo, Fermanagh and Clare. Early nameholders were Thomas and Denis O'Meehan, successively the bishops of Achonry, County Sligo, between the years 1251 and 1285, and from early times the sept were erenaghs of Devenish, County Fermanagh. Erenaghs were hereditary holders of church property. 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. Now generally recorded as Meehan, Meegan, Meighan, and others, the first recorded spelling of the family name and one of the earliest on record, is that of Edru O'Meighan. This was dated 1152, in 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 som,etimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.