The Irish surname Byrnes is an anglicized form of Gaelic Ó Broin meaning “descendant of Bran,” a personal name based on bran meaning “raven.” Bran was the name of a son of the King of Leinster, who died at Cologne in 1052, and also of the hero of an 8th century voyage tale. 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. The celebrated "Leabhar Branach" or "Book of the O' Byrnes" deals with the exploits of the clan in these times.