However, one major Irish surname is the exception to the rule. This is the house of McMurrough (Mac Murchadha), the ruling dynasty of the Gaelic kingdom of Leinster. Dermot McMurrough, the last old-style Irish king of Leinster, is famous or infamous in Irish history for inviting the first Anglo-Normans into Ireland, to help him fight the High-King Rory O'Connor and his personal enemey Tigernán O'Rourke, the king of Breifne. However, very few people in Ireland today have the surname McMurrough. This is because in later medieval times the McMurrough family divided into many branches situated all over north Co. Wexford and south Co. Carlow, each of whom adopted different surnames which survive and are indeed very numerous in Ireland today. One of King Dermot's sons was called Donal Cáemánach. This man is the ancestor of all the people called Kavanagh who live all over Ireland but mostly in Co.s Wexford and Wicklow. Other branches of the family adopted the surnames Kinsella (Cinnsealach), McDavymore and McVaddock (Mac Mhadóc), and there are a few more such surnames located mostly in north Wexford. Kavanagh and Kinsella are highly unusual Gaelic Irish surnames in that they never appear to have had a O or Mc prefix ever attached to them. Direct decendants of King Dermot McMurrough still live at Borris House in Co. Carlow, where the family preserved many treasures such as the Kavanagh Charter Horn.
One of my favourite characters in late medieval Irish history was the famous Art McMurrough Kavanagh, King of the Mountains of Leinster, who lived in the late fourteenth and early fifteenth centuries. Art was a very able Irish leader. He drove the descendants of the Anglo-Norman settlers out of north Wexford and coastal Wicklow and threatened the Anglo-Irish towns of Wexford, Carlow and Dublin, and it appears even gained some measure of control over the town of New Ross. Art Kavanagh became such a threat to the English interest in Ireland that the king of England, Richard II made two expeditions to Ireland to bring him to heel. On the first occasion King Richard forced Art Kavanagh to submit to him. However, the second time Art managed to remain at large. I have attached a contemporary illustration of a meeting Art Kavanagh had with the Earl of Gloucester. An English chronicler present at the meeting described Art Kavanagh as 'very stern and savage, and an able man'. The white horse that McMurrough is drawn riding to the meeting on was said to have cost him 400 cows.
The wars between King Richard II and Art McMurrough Kavanagh were very destructive. In 1394, McMurrough 'burned [New Ross], with its houses and castles, and carried away from it gold, silver, and hostages'. In 1398 English soldiers burnt down the monastic town of Glendalough in the Wicklow Mountains, and while Richard II was in Leinster, chasing Art McMurrough Kavanagh, he was deposed by his rivals in England. When Richard returned to England he was captured and murdered.
Art McMurrough Kavanagh remained at large as king of Leinster until 1416 or 1417, when he was poisoned in New Ross. Even in his last year he inflicted a great defeat on the Anglo-Irish of Wexford 'of whom he killed or took prisoner three hundred and forty'. Besides being a great Irish king, Art Kavanagh was also a great warrior. The Annals of the Four Masters record that in 1395 when the English tried to capture him 'by treachery', 'this was of no avail to them, for he escaped from them by the strength of his arm, and by his valour'. When McMurrough met the earl of Gloucester, it was recorded that 'In his right hand he bore a great long dart, which he cast with much skill'. When faced with such a talented Irish man it is no wonder that King Richard II met his match!