Sometime during the second half of the 13th Century, the Battle of Kilroe was fought between the invading force of Welshmen - composed of the Barretts and their sub-tribes who had invaded and conquered Tirawley - expelling the native tribes of the O’Dowds and the others who had rallied to make a united challenge.

The invading Welshmen were led by William More Barrett, who had conquered another batch of adventurers including the Cusacks, Browns and Moores who had built a fortified castle on their occupied territory at Meelick, near Killala. William More Barrett, who gave it to his kinsman Mac Wattin, speedily took this stronghold. The frustrated Cusack sought the aid of local clans and made an alliance with Tahilly O’Dowd out for revenge upon Barrett for the loss of Tirawley.

The opposing forces were drawn up at Moyne, where local lore still identifies the pillar stones which marked their respective positions. In the battle, Tahilly O’Dowd and his friend Tahilly O’Boyle were foremost in bravery and daring, and Cusack and his Irish auxiliaries carried the day. William More Barrett and one of his henchmen, Adam Fleming, were among the fallen and their supporters fled in despair. Many of them sought sanctuary in the nearby Church of Kilroe, but they were pursued by the vengeful victors, surrounded and butchered unmercifully.

The following year, O’Dowd was murdered by Cusack, who himself died 5 years later leaving Tirawley in the possession of the Barretts. The Norman family of the De Burgh eventually overcame them – one of whom was Thomas Óg Bourke of Moyne, holding the supreme title of the ‘Mac William’ or chief of the clan, was founder of Moyne Friary.