This is an Irish clan surname. It derives from the Gaelic O'Mianain, and was originally recorded almost exclusively in the county of Donegal. The name translates as 'the descendant of the son of 'Goodwill', and presumably the name was originally a nickname for a godly man, a hermit, or similar, one who dispensed goodwill. Many Irish surnames have similar semi-religious roots, roots which suggest that the nameholders, whilst not in holy orders themselves, were followers of holy men. In some cases the names suggest that the original holders were priests, and it is not generally known that the ban on the marriage of priests did not take effect until the 10th century, about 1000 years after the death of Christ. As it happens whilst not widely recorded, this is nethertheless one of the earliest of all Irish surnames. Unfortunately this 'fame' was bought at some cost, the first nameholder as shown below being executed at Sligo as a helpless hostage. It seems that he was being held by the Fitzgeralds as a surety for the behaviour of Conor O'Donnell, chief of the famous O'Donnell clan, to whom the O'Mianain was the tutor. Sadly O'Donnell failed to satisfy the terms of the agreement, and O'Mianain paid with his life. The first recorded spelling of the family name is shown to be that of Cormac O'Mianain, which was dated 1246, in the state records of Ireland, during the reign of King Henry 111 of England, known as 'The Frenchman', 1216 - 1272. 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.