Ireland´s political and constitutional dilemma is that two competing nationalisms emerged in the nineteenth century on the one small island. One was Irish nationalism which harked back to an ancient Gaelic civilization and was infused with Catholic culture and sometimes Anglophobic sentiment. The other was a regional dialect of British nationalism which took on a distinctly confessional character in Ulster. The aim of this paper is to identify the role of economic forces and the experience of economic change - a rather more subjective notion - in the development of nationalist and unionist movements in recent centuries. A fundamental part of the story, it is argued, lies with deep economic structures as well as temporally-bound and changing economic forces. The economic mattered but not only the economic.