Recorded as O' Byrne but more usually as Byrne, this is an Irish surname of great antiquity. Claiming descent from Bran, the king of Leinster, who died in 1052, this great clan originated in County Kildare where they held extensive territory until the Anglo-Norman invasion of Ireland in 1169 - 1170, when they migrated to Wicklow where they occupied the country between Rathdrum and Shillelagh. Their name in Irish is properly O' Broin, meaning the male descendant of Bron, the raven. The O' Broins, like their neighbours the O' Tooles, were particularly noteworthy for their resistance to foreign aggression, and they continued to inaugurate native chiefs up to the end of the 16th Century. The seat of their chiefs was at Ballinacor, County Wicklow, and the territory over which they held sway was known as Crioch Branach. The celebrated "Leabhar Branach" or "Book of the O' Byrnes" deals with the exploits of the clan in these times. Alderman Alfred Byrne (1882 - 1956), a distinguished recent member of the clan, was ten times Lord Mayor of Dublin. The Byrne coat of arms has the blazon of a red shield charged with a chevron between three silver dexter hands couped at the wrist, the Crest being a mermaid with comb and mirror proper. The first recorded spelling of the family name may be that of Fiacha Mac Hugh O'Byrne, the military leader. This was dated 1544 - 1595, in the Historical Records of Dublin, during the reign of Queen Elizabeth 1st of England, 1558 - 1603. 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.