Robert Brooke has kindly sent the following from "The Complete Peerage", Vol. iv, p.246 -
"Having, it is said, been benighted when out hunting, he unfortunately "was obliged to take up his lodgings at the Abbey of Feale, where he saw Katherine, the da. of one of his tenants, William MacCormicki, commonly called the Monk of Feale, and afterwards married her.Owing to this imprudent match, his friends and tenants abandoned him, and his uncle James thrice expelled him from his estates, and finally obliged him to surrender the Earldom in 1418. (a)
He then "pined away and died" at Rouen or at Paris, and was bur. at Paris, 10 Aug. 1420, in the Church of the Franciscans, or in that of the Dominicants.(b)"
(a)The Annals of Ulster, vol. iii, p. 60, and the Annals of the Four Masters, vol. iv, p.804, say that James banished him in 1411, but assign no reason.
Lodge states that the Earl made a formal surrender of the Earldom to his uncle James at Callan in 1418, and that James got the Earldom confirmed to himself and his heirs by Act of Parl. (there is nothing on the subject in the printed Statute Rolls).
Also that James gave to Morice, the Earl's son, "an Earl's son's portion of land," viz., the manore of Moyallow, Broghill, and Kilcolman.The existence of this Morice and his descendants (the FitzGeralds of Broghill and others, according to most genealogists) is awkward, as it renders, according to any known doctrine, all the subsequent Earls of Desmond upsurpers.
In a statement of claim to Decies (Carew MSS, vol.610.f.87), dated 1612, it is stated "Then cometh James.. to be Earl of Desmond, by unjust disinheriting of his nephew Thomas ... which was banished into Normandy, and there died without issue."
The Annals of the Four Masters entry M1411.8 may be found at :
but if you have difficulty you may have to start with :
and go on from there.
The Annals of Ulster have been captured, but I gather that they are yet to be put on-line.
The Carew MSS are in our local library which I will look up in the new year.