Does religion motivate and intensify nationalism, or does religion moderate and even suppress nationalism? Six kinds of relationships between nationalism and religion are critically reviewed: nationalism as a modern religion in competition with traditional religions; religious origins of the “Chosen People” as the mythomoteur of nationalism; religious exclusion as nation-building; religious influences on national policies; influence of religious observance on national identification; and religiously based “civilizations” transcending nationalisms. Western Christian experience with nationalism is not generalizable due to the institutional autonomy and supranational organization of the Catholic Church. Western European nationalisms were premised on religious sectarian homogeneity, and the homogenous “confessional state” served as the template of European nation-states. Furthermore, I argue that the late medieval eradication of Muslims and Jews across Western Europe prefigured sectarian and ethnonational purges of the following centuries. Finally, I argue that different configurations of religion and nationalism depend on two critical conditions: the degree to which the dominant religious tradition is doctrinally supraethnic and institutionally transnational, and the religious identity of the main adversary in the constitutive conflict that culminated in national statehood. The crises of Marxism and liberalism provide the context for the resurgence of religion and nationalism at present.

Modern historians have long argued that the early medieval Franks thought themselves to be the chosen people or new Israel, especially as they gained a great empire under the Carolingian dynasty in the late eighth century. The Opus Caroli of Bishop Theodulf of Orléans has often been cited as one of the clearest expressions of this self-conception as God's elect. A massive work attacking the legitimacy of the Byzantine empire in the context of the iconoclasm dispute during the early 790s, it does indeed contest the Byzantine claim to be the Christian empire. But Theodulf's repeated statement that ‘We are the spiritual Israel’ is best understood not as an assertion of ethnic election, but as a reference to the Christian tradition of Scripture exegesis which should (he argues) underpin both the Frankish and the Byzantine understanding of images. The Carolingian claim to empire rested on the Frankish championing of the universal Church, and its traditions of orthodoxy and correct biblical interpretation.