The marriage between a man of Norman ancestry and a woman of Gaelic blood was in violation of the Statutes of Kilkenny.

James FitzGerald took a leading role in forcing his nephew into exile in France where he died at Rouen two years later.

Although not acknowledged until 1422, he was in 1420 made Seneschal of Imokilly, Inchiquin, and the town of Youghal, by James Butler, 4th Earl of Ormond.

Along with his son-in-law Thomas FitzGerald, 7th Earl of Kildare, James was a prominent Irish supporter of the House of York.

Dying in 1462 or 1463, Desmond was buried at the Franciscan friary in Youghal.