The Byrnes can trace their ancestry to King Milesius, who came from Spain to Ireland in 558 B.C., and his son Heremon. The Byrne name itself, which originally would have been O'Byrne is derived from Broin from the personal name Bran, which is Irish for raven. The O'Byrnes were a leading clan in east Leinster and now one of the most numerous names in Ireland. In County Wicklow, homeland of the O'Byrnes, the remains of Black Castle can be seen on the cliff edge at Wicklow town.