The French annexation of the Papal States in 1808 was the culmination of a number of different trends both in French post-Revolutionary foreign relations and political culture as well as Napoleon's own political imperatives.

The abolition of existing polities and the redrawing of boundaries was a French policy that actually predated Napoleon's ascent to power and Italy was one of the laboratories for this process. As commander in the Army of Italy, Napoleon followed the orders of the Directory to establish various sister republics in the peninsula. These French client states would be run on efficient lines through local notables. The creation of the sister republics was in no small measure a reflection of Revolutionary missionary zeal that sought to replace obscurantism and allegedly feudal institutions with modern, enlightened ones. The sister republics also served the practical need of providing French armies in the region with supplies and requisitions helped shift the defense burden for France's wars from metropolitan France and onto French conquests. In this schema, Catholicism would either have to be subordinated to this project or have its political back broken. The latter course emerged as the preferred option since in the eyes of the French, the outsized influence of the church in the peninsula was the one of the principle causes of the region's backwardness and the French accordingly sought to break the political and social power of Catholicism inside these sister republics. Such sentiments frequently became wrapped up in the Revolution's anti-religious sentiments, but this zeal to break the old order was also a stalking horse for French chauvinism and cultural superiority; the practical, chauvinistic, and missionary elements of French policy often blended together. The Papal States were not immune to this process and the short-lived Roman Republic, proclaimed after an internal coup inside the city, led to French troops under Berthier's command to depose Pope Pius VI and began the process of modernizing the Republic into a French client state.

The Roman Republic did not survive the the brief reverse in France's continental fortunes in 1800 and Pius VI's successor, Pius VII, tried to have a more pragmatic relationship with the ascendant Napoleon. The French First Consul, for his part, also sought a more quiet relationship with the papacy after the stormy decade of the Revolution. However, both the papacy and Napoleon were increasingly at loggerheads during the Consulate. The Napoleonic successor to the Italian sister republics, the Kingdom of Italy, held the former papal territory of Romagna and despite Pius VII's entreaties, Napoleon refused to hand this region back to the Papal States. The introduction of the Napoleonic Code to the Kingdom of Italy, with such innovations like civil marriage and divorce laws, further led to yet more strains in French relations with the Papacy. The result was that despite Pius VII's presence at Napoleon's coronation, Napoleon's relationship with the Catholic establishment had deteriorated into a cold war despite Napoleon's Concordat.

This development had dire consequences for the future sovereignty of the Papal States under Napoleonic hegemony. The Papal States' coastal cities provided a useful pretext for annexation as this was yet another area in which the British could evade Napoleon's Continental blockade. The perception of papal resistance to Napoleon, both real and imagined, helped encourage the resurrection of earlier sentiments against the papacy that were common in the Revolution. The reports of Jacques Norvins, the Director-General of the Departmental police after the annexation were often filled with jeremiads against Italian laziness and their enablers in the Papal States. One 1813 report of Norvins is a useful window into the mentality justifying the annexation:

Rome has never acted as a sovereign state in its dealings with Europe. Its government was neither commercial nor warlike in character. It depended on the credulity of Catholics, on the spiritual influence of the great Saint, and so it could not make common cause with other governments, who all had age-old interests based on family ties, fleets, armies, and on tangible territorial power.

While the Napoleonic state began to see the papacy as a root of Italian resistance and backwardness, as exemplified by Norvins's reports, Napoleon began to invest the city with renewed symbolic importance once it was decoupled politically from the pope. Napoleon's great hope was that the city would become a second capital for the Empire and the reconstruction of Rome would hearken back to the days of Augustus and the glories of the Roman imperium. The edict announcing the annexation, displayed in large placards around the city, explicitly connected the ancient word empire to the new one:

Romans, the will of the greatest of heroes has reunited you with the greatest of states. It is fitting that the first people of the earth should share the benefits of their laws and the honor of their name with those, who in another age, preceded them along in the triumphal way.

French officials began a process of archeological work to restore Rome's various ruins such as the Temple of Jupiter, the Coliseum (which was being used as a religious site), and the Forum. Napoleon's son was fittingly given the title the King of Rome as he was the heir to his father's empire. As with the Kingdom of Italy, here were French-sponsored attempts to create an academy and other cultural institutions that would both glorify French power and incorporate Italian elites into the new regime. Similarly, the new Roman department instituted French legal norms like the civil code and the French regime instituted a reform of the system of taxation.

The reformist efforts of the French proved quite unpopular in both the Italian Departments and the Kingdom of Italy. Outside of the Italian elite, who often provied to be pliable servitors of the French state, there was very little popular Italian enthusiasm for French rule. Napoleon's "war" with Pius VII, which culminated in the excommunication of Napoleon and Pius VII's confinement in a fortress in Savona, underlay part of the unpopularity of France, but the religious angle was one of several facets of opposition to the Napoleonic regime. Both taxation and conscription were deeply unpopular intrusions into daily life and the Continental system created a deep economic depression in the peninsula. Not surprisingly, customs houses were a common target for mob violence during the collapse of French rule in Italy during 1813/14, and some prominent imperial officials, like the architect of the Kingdom of Italy's grand cadastral survey, Giusepe Prina, were lynched.

The abolition of the Papal States thus had several different well-springs. In some ways, Napoleon's actions towards Papal temporal authority were simply continuations of Revolutionary policies that promoted secularization and transformation of areas into new polities friendly to France and French interests. But Napoleon's imperial project shifted French policies towards the Papal States in which papal independence was counterproductive to Napoleon's own imperial ambitions. Thus older Republican sentiments about France's burden to uplift and civilize the Italians acquired an imperial gloss.

Sources

Broers, Michael. The Politics of Religion in Napoleonic Italy: The War against God, 1801-1814. London: Routledge, 2002.

Nicassio, Susan Vandiver. Imperial City Rome Under Napoleon. Chicago: University of Chicago Press, 2009.

Planert, Ute. Napoleon's Empire: European Politics in Global Perspective. Basingstoke: Palgrave Macmillan, 2016.