At the start of the nineteenth century, the Spanish Monarchy underwent a moment of profound crisis in which the sovereign powers of the king passed to local communities. This dissertation examines how that crisis altered the practice of politics in what became modern Spain. Utilizing the region of Western Andalusia as a case study, I explain how municipalities adapted to the advent of new political systems of rule beginning in 1808. I argue that the relationship between the central government and local governments changed in this period. At the middle of the eighteenth century, monarchy and municipalities enjoyed roughly equal status with one another. By 1823, the central government considered local communities subordinate to the will of the Spanish nation as a whole. Meanwhile, municipalities maintained a sometimes fierce defense of their political position vis-à-vis the central government. The transition from absolutism to constitutionalism that corresponded to the end of the Old Regime in Spain further contributed to the development of a more politically active and locally engaged population in Western Andalusia. War against the French roused deep sympathy for the patria chica. As Spanish patriots worked to reestablish political order under a series of juntas, local communities avoided ceding their sovereignty to centralized institutions. Local municipalities even interpreted central provisions of the Constitution of Cádiz (1812) to suit their needs in advance of those claimed by the nation. Thus, the advent of modern government in Western Andalusia was coupled with the intensification of localist political sensibilities.