Gerald, and his brothers-in-law, Geoffrey and Stephen, were against the King at the battle of Kildare [Cuirrech Liffe, i.e. the Curragh of Kildare, 1 Apr 1234, where Richard, Earl Marshal, was mortally wounded], and therefore were unable to obtain their purparties of Decies and Desmond, the inheritance of their wives.

1229 David de Rupe dies (maybe shortly before) and is succeeded by his second son, the "warlike" Gerald, his first, Reimund, being already dead. Reimund had had two daughters, and by English custom and law at that time they could not inherit their father's estate. Gerald inherited and they sued their uncle before the court of William Marescall, Earl of Pembroke, and failed. Gerald had married a daughter of Sir Thomas FitzAnthony. Gerald at about the same time also gained her father's lands when he died, being considered Thomas' sole male heir.