How did Napoleonic rule weaken the power of the Roman Catholic Church and aristocrats in conquered lands?

Napoleonic rule weakened the power of the Roman Catholic Church and the aristocracy in conquered lands primarily by exporting the principles of the Napoleonic Code, which mandated the abolition of feudalism and the establishment of civil equality.12

By replacing feudal structures with modern contractual forms of property, Napoleon dismantled the traditional economic and social foundations that supported the aristocracy. Furthermore, the secularization of civil relations—a core tenet of the Code—reduced the influence of religious institutions in public and legal life.12

Regarding the Roman Catholic Church, Napoleon’s policy was one of subordination rather than total destruction. Through the Concordat of 1801, he forced the papacy to accept the nationalization and sale of church property. By attaching "organic articles" to such agreements, he ensured the state maintained authority over church administration, effectively turning the clergy into "moral prefects" tasked with promoting obedience to the state rather than independent religious authority. This framework established a precedent where the church was integrated into the state apparatus, limiting its autonomy and political power across the empire.3456