O'Toole family

[1][2][3] According to historian C. Thomas Cairney, the O'Tooles were one of the chiefly families of the Uí Dúnlainge who in turn were a tribe from the Dumnonii or Laigin who were the third wave of Celts to settle in Ireland during the first century BC.

The first to use the surname in true hereditary fashion appears to have been the grandson of Tuathal Mac Augaire, Doncaon, slain at Leighlin in 1014.

The area they controlled was roughly identical to the old diocese of Glendalough, with the centre of their power in the region around the Glen of Imaal.

At the start of the 16th century, there were five great houses, all, owing allegiance to "The O'Toole of Powerscourt" as the recognized chief:[6] At the start of the 16th century, the leading branches of the clan were to a certain extent independent of each other; they were all bound to protect themselves; but in external matters affecting the whole clan they were bound to obey the head of the sept.[8] Throughout their history the family were famous as soldiers, from fighting the English in the glens of Wicklow to serving in the armies of other Catholic European countries in the 18th century, such as France and Spain.

The tradition of surnames in Ireland developed spontaneously, as the population increased and the former practice, first of single names and then of ephemeral patronymics or agnomina of the nickname type proved insufficiently definitive.