Ireland's status as a kingdom or as a colony continues to influence the historiographical debate about the country's relationship with the wider world during the early modern period. Interest in the continent is almost exclusively focused on exiles and migrants, rather than on diplomatic developments. Yet during the 1640s confederate Catholics in Ireland pursued an independent foreign policy, maintaining resident agents abroad, and receiving diplomats in Kilkenny. Following the execution of Charles I in 1649, they sought foreign assistance in their struggle against Oliver Cromwell. In alliance with the exiled House of Stuart, Irish Catholics looked to Charles IV, duke of Lorraine, as a potential saviour. For three years the duke encouraged negotiations in Galway, Paris, and Brussels. He despatched vital military supplies to Ireland, and attempted on at least one occasion to transport troops there from the Low Countries. Although his intervention ultimately failed to turn the tide of the war in Ireland, the English parliamentarians nevertheless believed he posed a serious threat. This detailed study of the duke's role, in the international struggle for Ireland during the early 1650s, largely ignored until now, helps to place the crises of the three Stuart kingdoms in their broader European context.