On Wednesday 17 January 1649, at a lavish ceremony in Kilkenny Castle, the Catholic Confederates signed a peace treaty with the lord lieutenant, James Butler, marquis of Ormond. In an emotional speech, the chairman of the Confederate General Assembly, Sir Richard Blake, hoped the agreement would ‘restore this nation in its former lustre’. Ormond responded generously, with a promise of further concessions from the king. In an uncharacteristically dramatic flourish, he announced: ‘There are no bounds to your hopes.’ The mutually congratulatory nature of these proceedings belied the six years of tortuous and often rancorous negotiations which preceded the agreement. Historians of the mid-seventeenth century have tended to focus on the bitter religious divisions of the period. But attempts by Confederates and royalists to clarify the constitutional relationship between Ireland and England proved equally controversial. The operation of Poynings' Law and increasing interference by the English parliament in Irish affairs emerged as the two key points of contention during peace talks.

In an article on the political thought of Patrick Darcy, Aidan Clarke argues that the Confederate stance on Poynings' Law was an issue of trust rather than constitutional principle. They were only interested in a suspension of the act in order to speed up the ratification of treaty terms by the Irish parliament, without interference from the king.