Now that tentative administrative, economic, and social schemas for the mudéjar society of the Ebro have been proposed, the final chapter of this work will address the mechanics of Muslim, Christian, and Jewish social interaction in the Crown. The way that members of the different faiths chose to and were permitted to defend both their local multi-confessional communities and the greater commonwealth which comprised the Crown provides one possible index of social integration. Christians, Muslims, and Jews each perceived of defense variably as a right, a duty, and an imposition, and acted accordingly, confronting rival municipal communities, local sectarian rivals, and the political enemies of their kings, according to how they perceived their own interests to lie. Service to the local community is analogous to defense, and it can be demonstrated that despite formal proclamations to the contrary, mudéjares did take part in the administration of aggregate municipal constituencies. But in an age traditionally qualified as one of Crusade and “Reconquest,” the importance of sectarian identity should not be understated. Hence the role of “political” ideology in the mudéjar experience must be examined, and the concept of the “frontier” in Iberian history reappraised, both in itself and as a factor which affected the lives of Muslims under Christian rule. It must be considered not only as a politico-military marker, but also as a zone of economic, technological, and cultural exchange.