Short answers, pulled from the story.
James fitz Maurice FitzGerald, 10th Earl of Desmond, was an Irish lord born around 1490 in Munster who died on the 18th of June 1529. He was the second but only surviving son of Maurice FitzGerald, the 9th or 10th Earl of Desmond, and he is notable for conspiring against Henry VIII with both King Francis I of France and Emperor Charles V.
James FitzGerald conspired with England's continental enemies as a strategy to gain external backing for his own position in Munster. He allied with King Francis I of France in 1522, recognizing Richard de la Pole as king of England; then, after Henry VIII switched sides and allied with France, Desmond switched to Emperor Charles V in 1528 and 1529.
In September 1521 James FitzGerald was defeated at the Battle of Mourne Abbey, south of Mallow in County Cork. The forces that beat him were led by Cormac Laidir MacCarthy, 9th Lord of Muskerry, allied with James's own uncle Thomas fitz Thomas FitzGerald, called "the Bald".
Emperor Charles V sent his chaplain Gonzalo Fernandez to meet with James FitzGerald at Dingle in 1528 or 1529. Fernandez reported back to the Emperor that the earl was between thirty and forty years old.
In 1525 Henry VIII sent Gerald FitzGerald, 9th Earl of Kildare, then Lord Deputy of Ireland, with an army to arrest James for treason following his 1522 conspiracy with Francis I of France. James evaded capture entirely.
When James FitzGerald died on the 18th of June 1529 without a male heir, his uncle Thomas fitz Thomas FitzGerald, called "the Bald", succeeded as 11th Earl of Desmond. James's only legitimate child, a daughter named Joan born in 1509 or 1514, was heir general but could not inherit the earldom.