Recorded as MacClancy, O'Clancy, Clancy, Clancey and the dialectal Glancey, this is a famous Irish clan surname. It is said that the original chief in the 12th century or thereabouts had a reputation for being in the thick of the fighting, and perhaps it is not surprising that one of the translations of the surname is 'the son of the red warrior' from the gaelic 'Mac Fhlannchaidh'. Certainly there has hardly been a time in Irish history when a member of the clan has not been closely involved. There are two main septs, the most important being centred on County Clare, and the village of Cahermacclancy, and to some extent the surrounding counties of Galway and Tipperary, whilst a smaller group can be found in County Leitrim. The original 'Mac' prefix was lost in the 17th century, but of late some nameholders have readopted it. The head of the Leitrim MacClancy sept is known as 'the Chief of Dartry', and up to the second seige of Limerick in 1691 the clan was very powerful in the West of Ireland. Thereafter many influential members took service abroad mainly as members of the famous Irish brigades in the army of France. The name has also been recorded in England from the 17th century and examples include Daniel Clansee, a witness at the church of St Katherine's by the Tower (of London), on April 22nd 1694, and Daniel Clancy, believed to be the son of the first Daniel, who married Martha Beesley at St Benets church, Pauls Wharf, London, on February 11th 1723. The first recorded spelling of the family name is shown to be that of Boetius MacFhlannchaidh, which was dated 1543, in the rolls of the Clan O'Brien. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.