My own county of Wicklow is also an excellent example of this Irish population trend. Today the surname Byrne is not only one of the most numerous surnames in County Wicklow, but also on the entire Island. O'Toole is also a very popular Wicklow surname. Both these families were also the Gaelic lords of the Wicklow Mountains for four centuries from the 1200s to 1603, and the two surnames have remained the most popular in the county despite the passage of time and many very destructive intervening wars and periods of displacement.
Before the invasion of Ireland by the Anglo-Normans in the years after 1169 AD, the O'Toole and O'Byrne families actually lived on the plains of Kildare. The ancestors of the O'Byrnes ruled north Kildare from their palace at Naas, while the O'Toole territory was in south Kildare where they had a famous ringfort at Mullaghmast. Before the Anglo-Norman invasion both families were expanding into the Wicklow Mountains. The O'Toole chieftains attempted to gain control of the monastic city of Glendalough. St Laurence O'Toole was made abbot of Glendalough by his father the O'Toole chieftain. My friend Dr Emmett O'Byrne also believes that some of the O'Byrnes were moving into the Shillelagh area of south Wicklow before the Anglo-Norman invasion.
When the Anglo-Normans invaded Ireland, places like the plains of Kildare, which were fertile and accesible were quickly taken by the Anglo-Normans, who built castles and settled colonists from Wales and England and expelled the native population. The Lord of the O'Tooles may have been killed by the Anglo-Normans and most of the family fled into the Wicklow Mountains. However, the O'Tooles were lucky. By this time St Laurence O'Toole was archbishop of Dublin and he settled his kinsmen on church lands in the Wicklow Mountains.
Before the Anglo-Norman invasion the local families who ruled Wicklow were called O'Farrell, O'Feary, and Mac Gilla Mo-Cholmóc. There were also Viking families in Arklow, Wicklow town and north Wicklow called Doyle, Archbold and Harold. The Anglo-Normans conquered east Wicklow and disspossed many of these families who disappeared and may have even died out, although the Hiberno-Norse families seem to have been left in place and the Mac Gilla Mo-Cholmócs were absorbed into the Anglo-Norman population, adopting the surname FitzDermot. The main Anglo-Norman familiy to settle in east Wicklow were the Lawlesses, who had their main castle near Rathdrum.
Things were quiet in the Wicklow Mountains until a period of bad weather around the year 1270. The Gaelic Irish in the mountain valleys may have been starving, so their leaders decided to rebel and attack the neighbouring Anglo-Norman communities who lived on all sides of them. This proved to be a major event in Wicklow history, and it changed the course of the county's history for four centuries. The rebellion was initially led by the O'Tooles, but the more powerful O'Byrnes soon took over. Many large English expeditions into the mountains were defeated and soon the O'Byrnes became powerful lords of Glenmalure and the O'Tooles lords of the the Glen of Imaal.
In the succeeding years the O'Byrnes and O'Tooles destroyed the Anglo-Norman colony in east Wicklow, and also drove the colonists out of all areas in the north of the county as far as Rathcoole and Saggart in south Dublin. The Lawlesses, Archbolds and Harolds were driven north where they survived in a reduced condition at Stillorgan, Greystones and other areas of south County Dublin. If any of the other families such as O'Farrell still survived by this time, they were totally dispossessed, mostly by the O'Byrnes.
The numbers of O'Byrne and O'Toole clansmen became very numerous, and their were many branches of these two families. The ruling O'Byrne family moved to east Wicklow where they had a castle at Newrath, near Rathnew. There were other branches of the main familiy living at Bollarney and near places like Ashford and Newtown. The ruling O'Toole family also left the Glen of Imaal to settle in Powerscourt and Castlekevin. Junior branches of the O'Byrne and O'Toole families were left ruling Glenmalure and the Glen of Imaal.
The O'Byrnes and O'Tooles continued as powerful Gaelic lords of the Wicklow Mountains until the end of the independence of Gaelic Ireland in 1603. The two families were the scourge of the English Pale and they became the hereditary enemies of the English of Dublin through their continous raiding of the areas south of the city. The Fitzgerald Earls of Kildare may have been able to put a stop to the raiding during their period as Lord Deputies of Ireland in the late fifteenth and early sixteenth centuries. The Mountains of Wicklow were one of the main strongholds of Gaelic independence throughout the wars of sixteenth century Ireland. In the 1530s, Turlough O'Toole of Powerscourt and lord of all the O'Tooles, was one of the most powerful chieftains in Gaelic Ireland. He drove the Fitzgeralds out of Castlekevin and Powerscourt and had contact with O'Neill and O'Donnell in Ulster. He travelled to England to meet King Henry VIII before being killed in the Glen of Imaal while trying to impose his authority on his distant O'Toole relatives then living in the valley. Amongst the O'Byrnes, it was the junior branch in Glenmalure which took over the leadership of the family in the sixteenth century. Feagh McHugh O'Byrne, the Lord of Glenmalure after 1579, was one of the most successful Gaelic Irish chieftains who fought the English in the latter half of the sixteenth century. In 1580 Feagh lured a large English army into Glenmalure before inflicting a serious defeat upon it in the valley. Feagh survived as Lord of Glenmalure until 1597, when he was tracked down and killed by Lord Deputy Russell. However, the O'Byrnes and O'Tooles remained a force in the Wicklow Mountains until the 1650s, when Luke O'Toole of Castlekevin and Brian O'Byrne of Glenmalure (Feagh's grandson), were prominent fighters against the Cromwellians.
Today Byrne and O'Toole are still very popular County Wicklow surnames, Byrne esecially so. O'Toole is very numerous in the north of the county around Bray, but members of the family are found in most parts of the county. Byrne is a very numerous Wicklow surname indeed, especially in east and south Wicklow. When I was in school there were many Byrnes in my class, only a few of them closely related to each other. Byrne is one of the few major Irish surnames where in modern times, holders of the surnames have not, in general added the O' back to their surname. I suppose Gallagher is another good example. Most people called O'Toole did adopt the O' throughout the late nineteenth and twentieth centuries as the Irish people became more nationalistic and took more of an interest in their often very distinguished family heritages. However, even in the sixteenth century, probably due to the close proximity of the Kavanagh and Kinsella families in north Wexford, who never had an O or Mc prefix to their name, the O'Tooles and O'Byrnes were often referred to simply as Tooles and Byrnes, so it is probably long-standing family tradition that the Byrnes have referred to themselves as such.
This has been quite a long blog but it is something I have long been interested in. Turlough O'Toole in particular is a figure from Wicklow history who interests me. I also very much like hill-walking in the Wicklow Mountains, and while on the summit of mountains in Glenmalure and in the Glen of Imaal it is very easy to picture O'Byrne and O'Toole clansmen roaming the hillsides in early modern times. The O'Tooles and O'Byrnes were two very distinguished Gaelic Irish families, also being two of the most capable and warlike ones. That the two families still dominate the Wicklow Mountains in terms of numbers of families with the surname is extraordinary given the passage of time since the era of the Gaelic lordships.