This chapter traces the origin of the 1798 rebellion in Ireland to that great destabilization in the Atlantic world provoked by Britain’s stunning victories in the Seven Years’ War, and the consequent acquisition of a worldwide Empire. These impacted on Ireland in that the quest for recruits to garrison this empire led directly to a repeal of many of the most stringent Penal Laws against Catholics, for Irish Protestants, a deeply unsettling development. In their turn, these triggered a continual political crisis in Ireland that was sharpened by the American crisis and the attendant whiff of British vulnerability. The French Revolution sent out mixed but powerful messages. Its Jacobin promise of liberty and equality found an eager audience in Ireland and elsewhere among those who were educated but marginalized. Among some Presbyterians the incredible events in France were viewed as a preliminary to the downfall of the Anti-Christ and as a prelude to the Second Coming. For many Irish Catholics, the message was also clear: the Jacobite moment had come and with it the real prospect of deliverance by a French invasion force. These mixed, sometimes contradictory strands led inexorably to armed rebellion in 1798.