This noble and distinguished surname, found almost exclusively in West Munster, is an Anglicized form of the Old Gaelic "O'Mathghamhana" (Modern Gaelic "O'Mathuna"), descendant of Mathghamhain, a male given name meaning "Bear". Traditionally, Irish family names are taken from the heads of tribes, revered elders, or some illustrious warrior, and are usually prefixed by "O", grandson, male descendant of, or "Mac" denoting "son of". Mathghamhain, progenitor of the great (O)Mahony sept, was the son of Cian and Sadhbh (daughter of Brian Boru, 4th Century High King of Ireland). The tract of land, over which his descendants held sway, extended from Cork to the Mizen Head, and the (O)Mahony chiefs were referred to in ancient Irish annals as "Rithe na Naoi bFonn" - Kings of the Nine Territories. Chief Diarmuid Mor O'Mahony (see below) assumed the leadership of the Fonn Iatharach or Western Territory early in the 11th Century, and in the course of time, his people built twelve castles, the best known of which are Rosbrin, Ardintenant, Dunmanus and Dun Locha (near the Mizen Head). A notable namebearer in the literary sphere was Sylvester Mahony (1804 - 1866), who wrote under the pseudonym of Father Prout. The (O)Mahony Coat of Arms is a shield divided quarterly with an azure lion rampant in the first and fourth gold quarters; a lion rampant counterchanged in the second silver and red quarters, and a red chevron between three snakes tongued proper in the third silver quarter. The first recorded spelling of the family name is shown to be that of Diarmuid Mor O'Mahony, which was dated 1028, in "Annals of the Fonn Iatharach", during the reign of High Kings of Ireland "with opposition", 1022 - 1166. 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.