The Irish surname of McGahey was derived fron Gaelic O'maolchathaigh, from Cathach, which means 'Warlike'. McGahey is numerous throughout Munster. Ireland was one of the first to use herditary surnames.A few herditary surnames were formed before the year 1000 but mostly came into being in the 11th century. As the Irish population increased it became necessary to broaden the base of personal identification. The prefix MAC was given to the fathers name . The prefix O was given to the grandfathers name. In the 16th century MacCahee was recorded in the Tyron Hearth Money Rolls . Many families migrated fron Scotland to Ireland in the 17th and 18th centuries and were granted lands of the native Catholic Irish. The McGahey Coat of Arms depicked a Lion, the noblest of all wild beasts. The Lion was used as a emblem of strength and valour.