Origins According to historian C. Thomas Cairney, the O'Byrnes were one of the chiefly families of the
Uí Dúnlainge who in turn were a tribe from the
Laigin who were the third wave of
Celts to settle in
Ireland during the first century
BC. The seat of the most famous branch of the
Ó Broin (
Uí Broin or
Branaigh) was at Ballinacor and controlled the surrounding lands, part of
Críoch Branach.
15th century and clan conflicts In 1402, the O'Byrne clan of County Wicklow, who periodically raided
Dublin, moved a large mercenary force to the banks of the
River Dargle at
Bray, but, as the direct route to the city would bring them close to the stronghold of
Carrickmines Castle, they apparently hesitated before attacking. The delay allowed the
Walsh family, who owned Carrickmines, to send an urgent warning to Dublin. The Dubliners responded decisively: the
Mayor of Dublin with a large force fell on the O'Byrnes and defeated them, in an encounter popularly known as the Battle of Bloody Bank, due to the number of casualties.
16th century and clan conflicts During the
Desmond Rebellions, the warlord Hugh O'Byrne gave support to the
Earl of Desmond, and died during the second rebellion. ==Heraldry==