It is widely accepted among secularisation theorists (Wilson 1966,1982; Dobbelaere, 1981; Berger 1981; Bruce, 1999,2002) that the more modern a society becomes, the more likely it is to secularise - i.e. the social and political significance of religion will most likely diminish. At the opposite end of the theoretical debate, scholarly work seeking to explain the recent phenomenon of the re-affirmation of religious values argues that the consequence of modernisation is not secularisation but rather the resurgence of religion (Huntington, 1996; Kepel, 1994; Juergensmeyer, 1993, 2000). With religion gaining salience in some societies but losing ground in others, this ongoing debate appears more critical than ever. The cases of Ireland and Greece are pertinent examples: The Republic of Ireland is experiencing secularising tendencies and the legitimacy of the Church is being increasingly challenged, while in Greece the role of religion remains strong, if not strengthened in recent years, and the legitimacy of the Church is maintained. For secularisation theorists, failure to secularise is likely in instances where there is an explicit link between religion and nationalism-'Cultural defence' or the 'nationalist pattern' (Martin, 1978). But while both cases constitute instances of cultural defence, Ireland is now secularising. This is precisely the puzzle this thesis is concerned with: where traditionally religion, culture and politics are linked, under what circumstances does religion cease to play a politicised and mobilising role, and under what circumstances is this role retained or even strengthened? This thesis argues that the answer can be found precisely in the nature of the nationalist pattern. Rather than being a monolithic model, there are significant variations within the pattern itself: religious based national identities, like all national identities, are fluid, not static. The dynamics of national identity change are dependent on two interlinked variables:(a) the degree to which a Church obstructs modernisation, and (b) external threat perceptions. This thesis will attempt to illustrate the inter-relationship between the above dynamics through a thematic comparison between Greece and Ireland. This model may be used to explain not only what accounts for the variations between the Greek and Irish cases, but also more generally to identify the conditions under which religion may remain or cease to be politically active and legitimate in societies where secularisation has been inhibited given a strong identification of religion with the nation.