Families of the Ó BYRNES A sept or family is a branch of a clan or a group believing itself derived from a common ancestor. The sept would have normaly been called after their ancestor eg. Ua Raghnall ( of Raghnall) or Ui Raghnall ( the Raghnalls) This subsequently was superceded by the Anglification to ' O' Byrne', the latter being a name used to cover all branches of the septs decended from Bran from around 1050ad. Today Byrne is the 5th most used surname in Ireland and is widely found throughout the world. The O'Byrne clan from its early periods developed into quite a number of different septs, partly because of disintegration of the main family( Ua Dunlang ) but this was mainly caused by the force of the Norman invasions pushing them from their traditional lands around Kildare, where they were known as Ui Faelan, King of Leinster who died in 737ad, towards the Wicklow mountains and on towards to eastern seaboard of Wicklow and Wexford and to the south into Carlow. There were four main septs located on the eastern coastal side of Wicklow and these septs shared the right to inaugurate a single Chieftain for the whole of their nation which was known as Crioch Branach ( The O'Byrne's Country ) others extended down to Carlow and Wexford Whilst each sept would have a head of their own to represent them the last recognised overall Chieftain to be inaugurated was DUNLANG Balbh (Dowling), 1578- 1580 of the Sept of CRONROE, in Crioc Branach. He was probably inaugurated on top of the Downes hill ( DunCaillighe Beirre, the fort of the old woman of Beirre) near Kilmacanoge, County Wicklow, see below for more details*. Due to the disintegration and collapse of the Clan system in Ireland from the 16th cent. on , no other chiefs were elected. In the 20th cent a number of ' Chiefs ' were elected but these were primarily for the purpose of providing a ' Chairman, Taoiseach, Tiarna, President, Ceannfine, etc ' for a commitee to organise special events , such as the 'Home Coming Festival ' in 1991, and family gatherings. Because of the fragmented nature of the Byrne clan there is now no proven direct lineage to any single previous O'Byrne Chieftancy as some other clans have. Up until recent times the Office of the Chief Herald did recognise about twenty hereditary Chiefs but this was ended because of abuses to their positions and also the lack of proven records of some pedigrees. So in Ireland today there are no officially recognised 'Clan Chieftains' by the Irish Government.