One of the most remarkable women of 16th century Ireland, Lady Margaret FitzGerald, a daughter of the eighth Earl of Kildare, is believed to have been born in 1473 and married in 1485 (at the age of 12) to Piers Butler, eighth Earl of Ormond: the couple would have nine children. A later chronicler, Richard Stanihurst described her as having been ‘man-like and tall of staure, liberal and bountiful, a sure friend and a bitter enemy, hardly disliking where she fancied, not easily fancying where she disliked.’ Other commentators thought her ‘a lady so politic, that nothing was thought substantially debated without her advice’ and as being ‘able for wisdom to rule a realm had not her stomach overruled itself.’ She certainly played an active role in her husband’s legal and dynastic affairs, enlarging or rebuilding many of Butler properties including Kilkenny Castle which the couple made their base. In Kilkenny she established the Grammar School in 1539 and during the previous decade brought over weavers and related craftsmen from the Low Countries to encourage the production of carpets and tapestries within their territories. In the 18th century historian Thomas Carte deemed Margaret FitzGerald ‘a person of great wisdom, and courage uncommon in her sex.’ In legend she is remembered for being on occasion extremely vindictive and cruel: many of the castles associated with her have windows or stone seats from which she is said either to have hanged her victims or watched them die. One story proposes that she ordered that seven bishops, all brothers, be robbed and killed. Another tells that while staying in one of her properties, she used to visit a nearby family, the Mandevilles and coveted their property. When they refused to part with it, she placed a curse on the Mandevilles so that all their sons died. The residence from which it is claimed she issued her malediction was Grannagh (or Granny) Castle, County Kilkenny.

Located on the northern bank of the river Suir just a few miles from Waterford city, Grannagh Castle is believed to have been built by the Le Poer family at the end of the 13th century. Around 1375 it passed into the hands of James Butler, second Earl of Ormond and remained with his descendants until seriously damaged c.1650. The early building comprised a large walled keep with cylindrical towers overlooking the Suir. Soon after taking possession of the property the Butlers seem to have erected a substantial five-storey tower in its north-east corner. Later additions included the insertion of an oriel window in the tower, and the construction of a double-height great hall adjacent to it along the south wall of the keep. The arch of a surviving window in that wall contains some carvings showing an angel holding the Butler coat of arms and the Archangel Michael wielding a sword in his right hand and the scales of Justice in his left. According to the 18th century historian and antiquary Edward Ledwich, during the Cromwellian war in Ireland, Grannagh Castle ‘was strongly garrisoned for the king, and commanded by Captain Butler. Colonel Axtel, the famous regicide, who was governor of Kilkenny, dispatched a party to reduce it, but they returned without accomplishing their orders; upon which Axtel himself marched out, with two cannon, and summoned the castle to surrender on pain of military execution. Without any hope of relief it is no wonder they submitted, and were conducted to the nearest Irish quarters.’ Thereafter the building stood unoccupied and seemingly allowed to sink into a ruinous state.