Part II. History of Thomond
Chapter 12. History of Thomond before it was formed into an English county: From the earliest times, to the death of De Clare, and expulsion of the English in 1318.

Their united forces defeated at Moygreasan; Death of Brian Roe under circumstances of savage atrocity by de Clare

In the meanwhile, Turlogh was busy seeking support for himself. He was joined by the MacMahons, that is, by Donogh son of Rory; and by Bryan, son of Teige Buidhe; by Cumeadha MacGorman; by Donald, son of Teige Alainn O’Brien of Tromraidh (Tromroe); and by Donald Mantach O’Connor Corcomroe; by the MacNamaras of Clancullein; and finally by the de Burgos and O’Kellys of Connaught. All these being ready, in the following autumn, they ravaged Moynoe and Tomgraney, and encountering Brian Roe and his auxiliaries at Moygreasan utterly defeated them in a pitched battle. In this engagement was killed Patrick Fitzmaurice, the brother of de Clare’s wife. This woman believing that her brother’s death and her husband’s defeat were occasioned by his connexion with Brian Roe, persuaded de Clare to invite that chieftain to Bunratty, and then to assassinate him. It was done according to her wish, and the murder was consummated under circumstances of peculiar atrocity. The parties were gossips. They had sworn mutually to defend one another, with the most solemn rites. They made oath upon bells and crozier, and upon the relics of the saints; blood was drawn from the veins of each and mingled in a vessel; the holy Eucharist was divided between them. In spite of these guarantees, O’Brien was torn to pieces by horses, at the command of his savage confederate. Such was the horror excited by this atrocious act, that it was referred to, as a proof of English perfidy, in the eloquent memorial presented, a few years afterwards, to Pope John XXII., by the chieftains of Ireland. ^[38] Brian Roe at his death left several sons; the eldest, named Donogh, assumed his father’s place.