From A Compendium of Irish Biography, 1878
Desmond, John, last of the line, a brother of the Sugan Earl, went to Spain in 1603, where he was styled Conde de Desmond. He was living in 1615, and died at Barcelona. His son Gerald, "choosing rather to trust to fortune, abruptly left Spain, and taking service in his Caesarian Majesty's army, served him well and chivalrously for three years; but at last, when he had the command of a strong town, then besieged, he was called on to surrender; this he refused to do, choosing rather to die of starvation than betray his trust. Thus did his career terminate."  Thomas, 10th Earl of Ormond, in right of his mother, Joan FitzGerald, daughter of the 11th Earl of Desmond, claimed the Earldom after the death and attainder of all the heirs male. When his daughter was married to James I.'s Scotch favourite, Sir Richard Preston, the title was conferred on him. When the only child of the latter, a daughter, was about to be married to the son of the Earl of Denbigh, the title was passed to the intended bridegroom. The marriage never took place; yet the title was retained, and is still held by the Earls of Denbigh.
54. Burke, Sir Bernard: Peerage and Baronetage.
147. Geraldine Documents: Edited by Rev. James Graves: in Journal of the Archaeological Association of Ireland, October, 1869.
216. Lodge's Peerage of Ireland, Revised and Enlarged by Mervyn Archdall. 7 vols. Dublin, 1789.