McGuire Coat of Arms / Mcguire Family CrestThis surname which is written as McGuire or Maguire, ranks among the forty commonest surnames in Ireland. It is interesting that in County Fermanagh, where their ancestors were once the ruling sept, Maguire families have today the commonest name in that county. The stronghold of the MagUidhire chief was at Enniskillen where their castle was built beside Lough Erne. Maguire is the most usual spelling, but in the west of Ireland the distinct prefix has more often been retained so that McGuire is the form favoured in County Mayo and County Roscommon. The name in Gaelic is rendered as 'odhargenuidhir' meaning 'dun-coloured'. Many members of this sept have been distinguished on the history of Ireland. Ireland was one of the earliest countries to evolve a system of hereditary surnames. They came into being fairly generally in the 11th century, and indeed a few were formed before the year 1000. At first the coat of arms was a practical matter which served a function on the battlefield and in tournaments. With his helmet covering his face, and armour encasing the knight from head to foot, the only means of identification for his followers, was the insignia painted on his shield, and embroidered on his surcoat, the draped and flowing garment worn over the armour. An early instance of the name was one Pierre Macquer (1718-84) who was a French chemist who wrote a popular textbook and the first chemical dictionary. He was descended from a Jacobite who had accompanied James II into exile in France. His surname is probably an altered form of Maguire and he may have been related to the Maguires who were Barons of Enniskillen. Surnames before the Norman Conquest of 1066 were rare in England having been brought by the Normans when William the Conqueror invaded the shores. The practice spread to Scotland and Ireland by the 12th century, and in Wales they appeared as late as the 16th century. Most surnames can be traced to one of four sources, locational, from the occupation of the original bearer, nicknames or simply font names based on the first name of the parent being given as the second name to their child.