Origin of the Name O'Mahony
family history was found in the allfamilycrests.com archives. The name O'Mahoney is derived from the Gaelic O'Mathghamhana sept that was taken from the Gaelic word 'mathghamhan' meaning 'bear'. Variants of the name O'Mahoney include O'Mahony, Mahoney and O'Mahony. When Gaelic names were anglicized during the sixteenth and seventeenth centuries they were often changed to Anglo equivalents that sounded most like their original Gaelic name. Their territory was the barony of Kineelmeaky which extended to the sea, where they had a fortified castle called Rosbrian off the coast of West Cork . Mathghamhan, whose mother Sadhbh was a daughter of Brian Boru, was the O'Mahony's ancestor. He was killed with many of his men at the Battle of Clontarf in the year 1014. Another famous bearer of the name was Count Daniel O'Mahony, General of the Irish Brigade in the service of France and hero of the battle of Cremona.
The O'Mahony coat of arms came into existence centuries ago. The process of creating coats of arms (also often called family crests) began in the eleventh century although a form of Proto-Heraldry may have existed in some countries prior to this. The new art of Heraldry made it possible for families and even individual family members to have their very own coat of arms, including all O'Mahony descendants.