The O’Byrnes and O’Tooles were surrogates for Art Mac Murrough Cavanagh who was the most powerful Chieftain in Leinster and recognised as a King amongst his own people. He used them to fight a proxy war against the English and thus avoid a complete break with them. Kellistown is situated in County Carlow between the towns of Carlow and Tullow.
"Here fell the heir presumptive to the English crown, whose premature removal was one of the causes which contributed to the revolution in England a year or two later."
Mortimer was none other than the heir to the Throne of England. He was also dignified with the titles ‘Earl of Ulster’ and ‘Lord Of Connaught’. Ironically he was a direct descendant of Aoife Murchada, whose father had let the English in. Thus he was a distant relation of his nemesis Art Mac Murrough Cavanagh!
Mortimer had been created the King of England’s Lieutenant in Ireland in 1396 and held this position until the Irish killed him. His body was cut to pieces during the battle but whether this as a result of combat or mutilation after his death is not recorded. Curiously enough he had decided to engage in the combat dressed in the Irish style - that is without body armour. There was at least enough of him remaining for his corpse to be brought back home to England where he was interred amongst his own people in Wigmore Abbey, Herefordshire.
King Richard II of |England was so upset by the news he resolved to return to Ireland and settle matters once and for all with Art Mac Murrough. But his departure from his own Country in 1399 cost him his Kingdom as his domestic enemies took the opportunity to topple him from his throne. On return in the month of August he was compelled to give up his crown and submit to the advances of his cousin, Henry of Bolingbroke. An embarrasment to the new King Henry IV he was allowed to wither away in captivity and ‘died’ - probably in early 1400.
An Cath Cell Osnadha was thus a battle of great importance in the history of two countries – England and Ireland.