On September 20, 1870, Italian troops breached the walls of Rome at Porta Pia and occupied the Eternal City, ending over a thousand years of papal temporal rule and completing the long struggle for Italian unification known as the Risorgimento. This decisive military action, ordered by King Victor Emmanuel II, marked the final chapter in the consolidation of the Italian peninsula under a single national government and transformed Rome from the capital of the Papal States into the future capital of the unified Kingdom of Italy.
The occupation represented far more than military conquest—it symbolized the triumph of modern nationalism over medieval religious authority and established the foundation for the complex relationship between the Italian state and the Catholic Church that would define Italian politics for the next century and beyond.
The Last Obstacle to Unity
Rome's incorporation into the Kingdom of Italy had been the final missing piece in the Risorgimento, as the city remained under papal control protected by French troops even after most of the Italian peninsula had been unified under the House of Savoy. The outbreak of the Franco-Prussian War in 1870 forced Napoleon III to withdraw French forces from Rome, creating the opportunity that Italian nationalists had awaited for nearly a decade to complete their territorial unification.
The Italian government's decision to occupy Rome was driven both by nationalist ideology and practical necessity, as the new kingdom required a capital city worthy of its ambitions and historically connected to Italian identity. Rome's symbolic importance as the ancient center of the Roman Empire and the heart of Italian civilization made it an irresistible prize for a nation seeking to establish its legitimacy and cultural continuity with the glorious past of the peninsula.
A Bloodless Victory with Lasting Consequences
The actual occupation of Rome proceeded with minimal violence, as Pope Pius IX ordered only token resistance to preserve the principle of papal sovereignty while avoiding unnecessary bloodshed in the holy city. Italian forces breached the Aurelian Walls after a brief bombardment, leading to the surrender of papal forces and the effective end of the Papal States as an independent political entity that had governed central Italy since the early Middle Ages.
The occupation immediately created what became known as the "Roman Question," a diplomatic and constitutional crisis over the status of the Pope as both a spiritual leader and a temporal sovereign who now found himself residing within the territory of a nation he refused to recognize. This unresolved conflict between the Italian state and the Vatican would persist until the Lateran Treaty of 1929, creating decades of tension that affected Italian politics, international relations, and the daily lives of Italian Catholics torn between loyalty to their nation and their church.
Transforming Italy and European Politics
The completion of Italian unification through Rome's occupation fundamentally altered the balance of power in Europe by creating a new major state in the center of the continent, while also contributing to the growing tension between traditional religious authority and modern secular nationalism that characterized late 19th-century European politics. Italy's achievement of territorial unity inspired other nationalist movements throughout Europe while demonstrating that the political map established by the Congress of Vienna could be successfully challenged through coordinated political and military action.
The occupation of Rome also marked Italy's emergence as a potential great power with imperial ambitions, as possession of the ancient capital encouraged dreams of restoring Italian influence in the Mediterranean and Africa that would shape the country's foreign policy for decades. More immediately, the creation of Rome as Italy's capital required massive investments in infrastructure, government buildings, and urban development that transformed the city from a sleepy papal town into a modern European capital, establishing the foundation for Italy's role as a major player in 20th-century European and world affairs.