Capture of Rome (1870)

Capture of Rome (1870) was the final military action in the Risorgimento that completed Italian unification by bringing Rome and the remaining Papal States into the Kingdom of Italy. The breach of the Aurelian Walls at the Porta Pia on 20 September 1870 followed the withdrawal of French Empire forces after the Franco-Prussian War, and precipitated the end of temporal power held by the Pope and the Papal States under Pope Pius IX. The event reshaped relationships among Italy, France, the Holy See, and European powers such as Prussia, Austria, United Kingdom, and Spain.

Background

In the decades leading to 1870, the Risorgimento movement led by figures including Giuseppe Garibaldi, Camillo Benso, Count of Cavour, Giuseppe Mazzini, and the House of Savoy sought unification of disparate Italian states such as the Kingdom of the Two Sicilies, the Grand Duchy of Tuscany, the Kingdom of Sardinia, and the Papal States. The First Italian War of Independence and the Second Italian War of Independence involved conflicts with Austrian Empire and diplomatic maneuvering with France under Napoleon III. The 1861 proclamation of the Kingdom of Italy left Rome and surrounding Lazio as the most significant unrecovered territory, protected by French garrison troops stationed in Rome since the 1849 suppression of the Roman Republic and the intervention against insurgents including followers of Mazzini and Carlo Pisacane. The 1866 Third Italian War of Independence and the Treaty of Vienna brought Venetia into Italy, while international law and instruments such as the Convention of September 1864 (resulting from the Convention of Rome) influenced arrangements over Rome and Papal authority. The outbreak of the Franco-Prussian War in July 1870 forced Napoleon III to recall the French corps, altering the strategic balance and inviting action by the Italian Government led by King Victor Emmanuel II and Prime Minister Giovanni Lanza.

Forces and Preparations

The Italian expeditionary element was organized by the Regio Esercito under the command of Raffaele Cadorna with subordinate leaders such as Alessandro La Marmora and involved units from divisions raised in Lombardy, Piedmont, Emilia-Romagna, and Tuscany. The Italian government mobilized artillery, engineers, and infantry brigades equipped with weaponry including Italian breech-loading rifles and field guns, and coordinated logistic support from ports like Civitavecchia and lines via the Pope's States railways. Opposing forces consisted of Papal Zouaves, irregulars loyal to Pius IX, Swiss and international volunteers, and a small contingent of Pontifical Guards commanded by officers loyal to the Holy See. The French garrison had withdrawn to garrison the Rhine front after orders from Emperor Napoleon III and his government in Second French Empire, leaving the Papal States defended by local and foreign clerical forces, supported politically by clerical allies in Austria-Hungary and sympathetic conservatives in the United Kingdom and Spain.

Battle and Entry into Rome

On 20 September 1870, Italian forces encamped near the Aurelian Walls at locations such as Saxa Rubra and Villa Ada and deployed artillery batteries to breach the walls near the gate of Porta Pia. After diplomatic ultimatums—the Ultimatum to Pope Pius IX—failed to secure peaceful transfer, Italian batteries opened bombardment; engineers placed mines and used pneumatic drills to create a breach. Exchange of fire occurred between Italian brigades and detachments of the Papal Zouaves and volunteers led by figures such as Lamoricière-era veterans and commanders loyal to Pius IX. The breach at Porta Pia allowed storming parties from units drawn from Bersaglieri and line infantry to enter Rome; fighting in the streets involved skirmishes around landmarks including Via Nazionale, the Quirinal Palace, and the Basilica of Saint Mary Major. Resistance ceased after the halt of papal military command and the capitulation of key positions; Italian troops raised the tricolor over municipal buildings, while representatives of the Kingdom of Italy began administration measures.

Political Consequences

The fall of Rome led the Italian Parliament to pass measures culminating in the Law of Guarantees and the annexation referendum in which citizens of the Papal States were presented choices under Italian administration. Victor Emmanuel II entered Rome and later established the Italian capital at Rome, moving ministries from Turin and Florence in processes involving politicians such as Agostino Depretis and Bettino Ricasoli. The loss of temporal power for Pius IX crystallized the Roman Question debated in diplomatic salons in Paris, Berlin, Vienna, and London and in negotiations involving the Holy See and the Kingdom of Italy. The event altered alignments that involved the newly proclaimed German Empire under Otto von Bismarck, whose victory in the Franco-Prussian War indirectly enabled Italian action, and complicated relations with the Second French Empire.

Aftermath and Integration into Italy

In the months and years after 1870, Italian authorities implemented administrative integration of former Papal States territories through laws, census operations, and reform of municipal institutions in Lazio, Umbria, and Marche. The Lateran Treaties would only later settle the Roman Question in 1929 between the Kingdom of Italy under Benito Mussolini and the Holy See led by Pope Pius XI, creating the Vatican City as a sovereign state. Cultural and urban projects in Rome under architects and planners influenced conservation of monuments like the Colosseum and the Forum Romanum and modernization of institutions including the University of Rome La Sapienza and national museums such as the Museo Nazionale Romano. Veterans and participants from the operation influenced Italian politics and commemoration in memorials, while relations among Italy, France, Austria-Hungary, and the Holy See continued to shape European diplomacy into the 20th century.

Category:Battles involving Italy Category:19th century in Rome