The death of Joan Fitzgerald countess of Ormond Ossory and Desmond at Askeaton County Limerick on 2 January 1565 represented more than the demise of one of the most politically influential and wealthy women in late sixteenth-century Ireland; it also heralded the collapse of the peace between her husband and her son that she had brokered and maintained in her native province of Munster during the previous decade. In the generation before Joan, her mother-in-law Countess Margaret Fitzgerald, wife of Piers Butler eighth earl of Ormond, also held a key position within the Ormond dynasty and among the small coterie of influential aristocratic women in late medieval Ireland. The two women operated in very different spheres; Joan was active in political circles in Munster, Dublin and London and was a personal confidante of Queen Elizabeth I, whereas Margaret concentrated her energies on stabilising and strengthening the Ormond dynasty as well as modernising the patrimony. Yet, in different ways, each played a very significant role in determining the fortunes of the family and of the earldom. Joan and Margaret were, of course, outstanding though not exceptional among their peers in terms of the influence and control they exerted; for that reason, they are familiar figures in modern histories of late medieval and early modern Ireland.