The Capture of Rome (20 September 1870)

The capture of Rome is one of the best documented events of the 19th century. It took place in the full age of the press, photography and modern administrative archives. The difficulty, for the historian, is not a lack of sources but sorting the propaganda: the heroic narrative of the Risorgimento on one side, the narrative of spoliation and martyrdom on the other.

Official and diplomatic documents

The event is framed by a series of dated, public documents. The exchange of letters between Victor Emmanuel II and Pius IX (letters of 8 and 11 September 1870) fixes the political confrontation; it was printed at the time and appears in the diplomatic collections^[7]. On the pontifical side, the acts of Pius IX — the encyclical letter Respicientes ea omnia of 1 November 1870, then Ubi nos of 15 May 1871 — are preserved and accessible on the Holy See's website; they constitute the official magisterial response to the conquest^[8][9]. On the Italian side, the Law of Guarantees of 13 May 1871 and the decree making Rome the capital (law of 3 February 1871) were published in the kingdom's bulletin of laws^[10].

Witnesses and memorialists

General Raffaele Cadorna, who commanded the expedition, left a detailed account, La liberazione di Roma nell'anno 1870 ed il plebiscito (Roma-Torino, Roux, 1889), a first-hand source on the military operations, even though it was written by the victor and justifies his action^[11]. On the pontifical side, the reports of General Hermann Kanzler and the many memoirs of Papal Zouaves — those Catholic volunteers come from all over Europe — give the defenders' point of view^[12]. Photography enters history here: the Roman Ludovico Tuminello photographed the breach in the immediate aftermath of the assault — the current reproductions date this print to 21 September 1870 — delivering one of the first documentary images of a European act of war^[13].

Historiography: from myth to critical work

For decades, official Italian historiography celebrated 20 September as a founding, liberating act, while intransigent Catholic historiography saw in it pure sacrilege. Modern critical work has moved beyond both narratives. The reference scholarly biography of the pope is that of the Jesuit Giacomo Martina, Pio IX, in three volumes published at the Gregorian University (volume 3 covers 1867-1878): it assesses with nuance the responsibility of Pius IX as sovereign^[14]. For the French framework, Roger Aubert gave an authoritative synthesis in Fliche and Martin's Histoire de l'Église^[15]. On the English-speaking side, Owen Chadwick (A History of the Popes 1830-1914) and, in a more polemical vein, David Kertzer (Prisoner of the Vatican) renewed the analysis of the "Roman Question"^[16][17].

To understand the emotion of 1870, one must first understand what is at stake: not a mere city, but a sovereign State led by the pope since the early Middle Ages.

The Papal States, a thousand-year-old State

The Papal States (or States of the Church) were born in the 8th century, when the king of the Franks Pepin the Short gave the pope, in 756, the territories wrested from the Lombards — the famous "Donation of Pepin" ^[18]. For more than a thousand years, the pope was thus both the spiritual head of Catholicism and the temporal monarch of a vast territory covering Rome, Latium, Umbria, the Marches and Romagna. This twofold function was regarded, in the doctrine of the time, as a guarantee of independence: a pope subject to another prince risked becoming the instrument of his policy.

At its peak, this State made the pope one of the great sovereigns of Europe. But in the 19th century, the pontifical government — clerical administration, ecclesiastical justice, no modern constitution — was perceived by liberal elites as an anachronism. The insurrections of 1831, then of 1848-1849, showed that the legitimacy of temporal power was deeply contested within its own borders^[19].

The Risorgimento and the "Roman Question"

The Risorgimento — the Italian national unification movement — made Rome its supreme objective. For the patriots, a united Italy without Rome as its capital was inconceivable: "Roma capitale" became a watchword. But Rome was the seat of the pope. The whole difficulty lies there: to annex Rome was to despoil the Holy Father.

From 1859-1861 onward, the Kingdom of Sardinia, led by Victor Emmanuel II and his minister Cavour, unified the peninsula at an accelerating pace. In 1860, the Piedmontese army invaded the Marches and Umbria, crushing the pontifical army at the Battle of Castelfidardo (18 September 1860)^[20]. The Papal States were thus reduced to Latium alone around Rome. The Kingdom of Italy was proclaimed in March 1861. It lacked only two pieces: Venetia (obtained in 1866) and Rome.

France's protective role (1849-1870)

What prevented the capture of Rome for twenty years was not the small pontifical army, but France. In 1849, Louis-Napoleon Bonaparte — soon Emperor Napoleon III — had sent an expeditionary corps to overthrow the ephemeral Roman Republic and restore Pius IX, who had fled to Gaeta. Ever since, a French garrison had been stationed at Rome to protect the pope, out of regard for the French Catholic opinion on which the emperor depended^[21].

This protection placed Napoleon III in an untenable position, torn between French Catholics and Italian nationalists. The September Convention (1864) provided for a French withdrawal in exchange for the Italian commitment to respect pontifical territory; the French troops left in 1866. But they returned as early as 1867.

Mentana 1867 and the chassepots

In October 1867, Giuseppe Garibaldi launched an expedition of volunteers against Rome, crying "Roma o morte" ("Rome or death"). France hastily sent back an expeditionary corps which, allied with the pontifical troops, crushed the Garibaldians at the Battle of Mentana on 3 November 1867^[22]. The French soldiers christened there a new rifle, the chassepot, whose superiority worked wonders. General de Failly telegraphed the emperor a sentence that has remained famous:

"Sire, the Chassepots worked wonders!" — General Charles de Failly, telegram to Emperor Napoleon III, November 1867^[23]

Mentana sealed, for three more years, the maintenance of a French garrison at Rome. As long as Napoleon III's soldiers stood watch, Italy dared not cross the pontifical frontier. The capture of Rome was simply waiting for the moment when France could no longer defend the pope.

The man who occupies the throne of Peter in 1870 is a considerable figure, whose long reign — the longest in the history of the papacy after that of Saint Peter — frames the whole crisis.

From the "liberal pope" to the "pope of the Syllabus"

Elected on 16 June 1846, Pius IX — Giovanni Maria Mastai Ferretti — first passed for a reformer. His first measures (political amnesty, easing of censorship, modernisation projects) earned him immense popularity and the nickname of the "liberal pope" ^[24]. But the revolution of 1848, the assassination of his minister Pellegrino Rossi, and his flight to Gaeta before the Roman Republic, turned him durably. Restored by French bayonets, he became the pope of intransigence toward the modern world.

This evolution culminated in 1864 with the encyclical Quanta Cura and its appendix, the Syllabus of modern errors, which condemned rationalism, liberalism, socialism and the claim to subject the Church to the State^[25]. The last condemned proposition — according to which "the Roman Pontiff can and ought to reconcile and harmonise himself with progress, liberalism and modern civilisation" — became the symbol of a head-on rupture with the spirit of the age. On the political plane, it meant that Pius IX would never voluntarily renounce temporal power.

The First Vatican Council and infallibility (18 July 1870)

It was in this climate that Pius IX convened the First Ecumenical Council of the Vatican, opened on 8 December 1869. Its most resounding act was the definition, by the dogmatic constitution Pastor Aeternus, of pontifical infallibility and the pope's primacy of jurisdiction, voted on 18 July 1870^[26].

"The Roman Pontiff, when he speaks ex cathedra […] enjoys, by the divine assistance promised to him in blessed Peter, that infallibility with which the divine Redeemer willed His Church to be endowed." — First Vatican Council, constitution Pastor Aeternus, ch. IV, 18 July 1870^[27]

The coincidence of dates is striking. The council strengthened the pope's spiritual authority at the very moment he was losing all temporal authority. The day after the vote, on 19 July 1870, France declared war on Prussia: the machine that would sweep away temporal power had just been set in motion. On 20 October 1870, a month after the capture of Rome, Pius IX suspended the council sine die by the bull Postquam Dei munere; it was never resumed, then was formally closed by John XXIII in 1960, on the eve of the Second Vatican Council^[28].

The Italian government's calculation was simple: Rome would fall as soon as France could no longer defend it. The summer of 1870 offered that opportunity.

The withdrawal of the French troops

The Franco-Prussian War, declared on 19 July 1870, required the recall of all available French forces. The withdrawal of the Rome garrison was ordered at the beginning of August 1870; the last French soldiers left Civitavecchia in the following weeks^[29]. Then came the catastrophe: on 2 September 1870, the French army capitulated at Sedan and Napoleon III was taken prisoner. On 4 September, the Second Empire collapsed and the Republic was proclaimed in Paris.

The pope's protector had vanished within days. The Italian government, led by Giovanni Lanza and Quintino Sella, understood at once that the hour had come: an Italy that failed to act risked seeing the republican and Garibaldian party seize Rome in its place, which would have been both more violent and more dangerous for the Savoy monarchy^[30].

Victor Emmanuel II's letter (8 September 1870)

Rather than a brutal invasion, the king wanted to keep up the appearance of a peaceful approach. He dispatched to the pope Count Gustavo Ponza di San Martino, bearer of a letter dated 8 September 1870. The king presented himself to the pope — "with the affection of a son, with the faith of a Catholic, with the honour of a king, with the feeling of an Italian" — invoking public order and the pontiff's protection to request the entry of his troops^[31].

The letter presented the occupation as an "unavoidably necessary [measure] for the safety of Italy and of the Holy See", and asked the pope to authorise the entry of the royal troops "for the maintenance of order" and the protection of the pontiff's person^[32]. It was asking the victim to bless the theft.

Pius IX's reply

The pope received the count on 10 September and answered him in writing on 11 September 1870. His letter, short and icy, refused everything:

"I cannot admit the requests expressed in your letter, nor adhere to the principles it contains. […] I pray God to grant abundant graces to Your Majesty, to deliver you from every peril." — Pius IX, letter to Victor Emmanuel II, 11 September 1870^[33]

Receiving the messenger, the pope gave vent to his bitterness at what he called a useless hypocrisy — "I may indeed yield to violence, but give my sanction to injustice — never!" (words reported by O'Clery, a contemporary Catholic author)^[34]. The meaning was clear: Pius IX would never yield of his own free will. He compelled Italy to take Rome by force of arms, so that the spoliation would be manifest in the eyes of the world and his protest would keep its full juridical value. As early as 11 September, General Cadorna had received the order to cross the pontifical frontier.

The balance of forces was overwhelming. This was not a real battle, but a demonstration.

Cadorna's Italian army

General Raffaele Cadorna had the IV Army Corps, some 50,000 men massed around Rome, including infantry battalions, cavalry, and the elite corps of the bersaglieri (foot riflemen famed for their speed, recognisable by their feathered hats)^[35]. The troops crossed the frontier on 11 September 1870 and advanced almost without fighting. Civitavecchia, the pontifical port, surrendered on 16 September. On 19 September, the Italian army encircled Rome.

The small pontifical army and the Zouaves

Facing them, General Hermann Kanzler, pro-minister of Arms, had only about 13,000 men^[36]. This small army had a remarkable particularity: it was international and voluntary. Its most famous corps, the Papal Zouaves, gathered young Catholics from France, Belgium, the Netherlands, Canada, Ireland, Austria, Spain and elsewhere, who had chosen to take up arms to defend the pope out of pure religious conviction^[37]. Alongside them served pontifical carabinieri, the Antibes Legion (Frenchmen) and various volunteers.

But these men, courageous and devoted, were poorly armed, devoid of modern artillery and deprived of the only support that mattered: France. Militarily, the outcome was in no doubt. Their sacrifice could only be symbolic — and that is precisely what the pope asked of them.

Pius IX's order: a "pro forma" resistance

The heaviest decision of the day was not military but moral. Pius IX gave General Kanzler an explicit order: to offer a resistance sufficient to establish the fact of violence, but to stop as soon as a breach was opened, so as to avoid useless bloodshed^[38]. The pope wanted a witness, not a massacre.

"As regards the duration of the defence, I feel it my duty to command that this shall only consist in such a protest as shall testify to the violence done to us, and nothing more. In other words, that negotiations for surrender shall be opened as soon as a breach shall have been made." — Pius IX, letter to General Kanzler, Vatican, 19 September 1870 (text reproduced by O'Clery; English translation by Ignispedia)^[39]

This order explains the whole character of 20 September: a combat that was real but brief, few dead, and a swift capitulation. The resistance had to be serious enough for no one to claim that the pope had abandoned Rome willingly; it had to stop early enough for the blood shed to remain minimal.

The bombardment and the breach

In the early hours of Tuesday 20 September 1870, at about 5:10 in the morning, the Italian artillery opened fire on the Aurelian Wall, Rome's ancient enclosure, on the sector between Porta Pia — whose inner façade had been designed by Michelangelo — and Porta Salaria^[40]. The fire concentrated on one point to open a gap in it.

After about five hours of bombardment, a breach some thirty metres wide opened in the wall. At about 9:30-10 in the morning, the bersaglieri rushed through it, followed by the infantry. Italian military tradition has made this instant a founding moment: the riflemen crossing the rubble to the sound of the trumpet^[41]. The first hand-to-hand fighting took place in the district, around Villa Patrizi and along the via that today bears the name of "via XX Settembre".

The chronology of the morning can be summed up as follows:

The white flag and the capitulation

In accordance with his instructions, the pontifical command had the white flag raised as soon as the breach was carried, at about 10 in the morning^[42]. General Kanzler then ordered the ceasefire. The fighting had lasted only a few hours. In the evening, the capitulation convention was signed: the pontifical army, about 13,000 men, laid down its arms; the foreign volunteers would be repatriated.

The convention initially provided for leaving the pope the Leonine City — the district around the Vatican and the Borgo, on the right bank of the Tiber. But, as early as 21 September, the pope himself asked the Italian commander to send his troops in to prevent disorder^[43]. The pope found himself confined to the Vatican palace alone and its immediate dependencies. The whole Eternal City was now in the hands of the Kingdom of Italy.

The human toll

The fighting claimed relatively few victims, in keeping with the semi-symbolic character of the resistance. General Cadorna gives, in his memoir, the toll for the whole Latium campaign (11-21 September 1870), and all syntheses agree on a limited toll^[44]:

For the single day of 20 September, the nominal lists drawn up afterwards count 48 Italians killed; on the pontifical side, the dead of the day and the wounded who died of their wounds in the following weeks bring the total to about twenty. The scale remains modest for the conquest of a capital: it is the direct consequence of Pius IX's order not to shed blood uselessly^[45]. The soldiers who fell that day — Italian as well as pontifical — would afterwards be honoured on both sides, each according to his camp.

The military conquest had to be turned into a legitimate annexation. The Italian government organised a plebiscite for that purpose.

The plebiscite of 2 October 1870

On 2 October 1870, the inhabitants of Rome and Latium were called to vote yes or no on union with the Kingdom of Italy under Victor Emmanuel II. The result was a landslide in favour of annexation:

These overwhelming figures^[46] must be read with the historian's hindsight: the ballot took place under military occupation, with no guaranteed secrecy, and a large share of the Catholics loyal to the pope abstained on principle, refusing to endorse the spoliation. The plebiscite thus reflects both a genuine national aspiration on the part of some Romans and the pressure of the context. In terms of the international law of the time, it offered Italy the appearance of popular legitimacy.

Rome, capital of Italy

By the law of 3 February 1871, Rome was proclaimed capital of the Kingdom of Italy, supplanting Florence (which had itself held that rank since 1865, after Turin)^[47]. During 1871, the king, the government and Parliament settled in the Eternal City. The Quirinal, the popes' former summer palace, became the royal residence — a painful symbol for the Holy See, which saw in it a further usurpation. The Risorgimento's dream was fulfilled: Italy was unified, from Turin to Sicily, around its historic capital.

Here begins the long spiritual and diplomatic crisis known as the "Roman Question", which would poison relations between the Church and the Italian State for nearly sixty years.

The protest: Respicientes ea omnia

On 1 November 1870, Pius IX published the encyclical letter Respicientes ea omnia. In it he solemnly protested against the "unjust, violent, null and sacrilegious invasion" of his States, declared null all acts accomplished against the rights of the Holy See, and declared incurred the major excommunication against the invaders and usurpers of his provinces and of Rome — as well as their principals, partisans and auxiliaries — according to the form of his apostolic letter of 26 March 1860 (numbered passage §13, known as "of the usurpers," in the English version)^[48].

"We declare that this invasion […] is unjust, violent, null and void." — Pius IX, encyclical letter Respicientes ea omnia, 1 November 1870^[49]

By this same act, the pope laid down the principle that would govern his attitude until his death: considering himself despoiled by force and deprived of the liberty needed for the serene exercise of his ministry, he refused all recognition of the fait accompli and declared himself a prisoner.

The Law of Guarantees (1871) and the pontifical refusal

The Italian government wanted to settle the pope's status unilaterally. The Law of Guarantees (Legge delle Guarentigie) of 13 May 1871 granted the Sovereign Pontiff exceptional prerogatives: his person was declared sacred and inviolable, he kept the use of the Vatican and Lateran palaces and the villa of Castel Gandolfo, enjoyed sovereign honours, the right of legation, and received an annual endowment of 3,225,000 lire^[50].

Pius IX categorically rejected this law. In his eyes, a guarantee granted by a law of the Italian State — hence revocable at any moment by that same State — was worth nothing: it made the pope a subject at the mercy of Rome's goodwill, not an independent sovereign. By the encyclical Ubi nos of 15 May 1871, he denounced the law as unacceptable and refused the endowment, which was never touched by the Holy See^[51].

"These guarantees […] cannot in any way assure Us that full and solid liberty which, by divine institution, We need in order to govern the universal Church." — Pius IX, encyclical letter Ubi nos, 15 May 1871^[52]

The Non Expedit

Pius IX drew one last consequence from the situation: he forbade Italian Catholics to take part in the national political life of the usurping kingdom. This instruction, summed up by the Latin formula Non expedit ("it is not expedient"), was uttered by Pius IX in audience on 11 October 1874, then proclaimed as a prohibition by the Holy Office on 30 December 1886 (non expedit prohibitionem importat): the faithful were to be neither voters nor candidates in Italian legislative elections^[53]. The aim was not to recognise the legitimacy of the State born of the spoliation.

The Non expedit weighed heavily on Italian political life for a generation, keeping Catholics out of Parliament and leaving the field open to liberals and secularists. It was progressively relaxed by Saint Pius X (from 1904-1905 onward, notably by the encyclical Il fermo proposito of 11 June 1905), then abolished by Benedict XV in 1919, with the birth of Don Luigi Sturzo's Italian People's Party^[54].

A voluntary confinement of 59 years

From 20 September 1870 onward, Pius IX never again crossed the Vatican enclosure, and his successors imitated this attitude. Leo XIII (1878-1903), Saint Pius X (1903-1914), Benedict XV (1914-1922) and Pius XI (1922-1939, until 1929) likewise remained voluntary "prisoners," refusing to endorse by their free movement the loss of Rome. For fifty-nine years, the pope was a sovereign without territory, recognised by the Catholic powers but deprived of any State^[55]. Pius IX died at the Vatican on 7 February 1878, without having yielded.

Beyond the political drama, the capture of Rome raises a properly theological question: was the loss of temporal power a misfortune for the Church, or a blessing in disguise?

The Catholic gaze: the end of a burden

At the time, almost all Catholics experienced the event as a catastrophe and an injustice. But, with time, another gaze prevailed, including within the Church itself. By ceasing to be a temporal prince mixed up in diplomatic intrigues, questions of taxation and policing, the pope found himself set free for his spiritual mission. Leo XIII, from the end of the 19th century onward, was able to redeploy a moral diplomacy and a social doctrine (Rerum Novarum, 1891) of universal scope such as the sovereign of a small Italian State could never have had^[56].

The historian Owen Chadwick summed up this paradox: the papacy gained in moral authority what it lost in political power. Deprived of army and territory, the pope was no longer suspected of defending earthly interests; his word became, for the whole world, that of a disinterested conscience. The Catholic gaze recognises retrospectively in the fall of temporal power a design of Providence, which uses even the injustices of men to purify His Church.

Leo XIII, Pius X, Pius XI: toward reconciliation

The crisis could not last forever. The successive popes, while maintaining the protest in principle, gradually let Catholics rejoin Italian society. Participation in the First World War, in which Catholics and patriots fought side by side, brought hearts closer together. When Pius XI ascended the throne in 1922, he gave from the day of his election, 6 February, his first Urbi et Orbi blessing from the outer loggia of Saint Peter's, overlooking the square — a symbolic gesture of openness after fifty-two years of blessings given from within^[57]. The way to reconciliation was open.

The end of the Roman Question

The solution came from a new power: the Fascist regime of Benito Mussolini, which came to power in 1922, sought to conciliate the Church to establish its legitimacy. After years of secret negotiations conducted on the pontifical side by the Cardinal Secretary of State Pietro Gasparri, the Lateran Agreements (Patti Lateranensi) were signed on 11 February 1929 at the Lateran Palace^[58]. They comprised three texts: a political treaty settling the territorial question, a concordat governing Church-State relations in Italy, and a financial convention compensating the Holy See for the property lost in 1870.

Vatican City State

By the treaty, Italy recognised the full sovereignty of the Holy See over a tiny but real territory: Vatican City State, of about 44 hectares, of which the pope became once more the temporal sovereign — no longer a great State, but just enough land to guarantee his absolute independence^[59]. The financial convention provided for the payment of 750 million lire in cash and one billion lire in State bonds^[60]. In return, the Holy See recognised the Kingdom of Italy with Rome as its capital, definitively settling the wound of 1870.

Pius XI summed up the meaning of these agreements in a formula that has remained famous, in which he acknowledged in this unexpected reconciliation the hand of God:

"Perhaps a man was needed like the one whom Providence made Us meet." — Pius XI, address to the professors and students of the Catholic University, 13 February 1929^[61]

Fifty-nine years after the breach of Porta Pia, the Roman Question was closed. The Church had not recovered its States — nor, indeed, did it want them any more — but it had obtained the essential: an islet of sovereignty guaranteeing that the Successor of Peter would never again be any prince's subject. 20 September 1870, which had seemed to be the end of a thousand-year-old institution, had finally proved to be the painful step toward a papacy freer and more universal than ever.

• The Papal States (756-1870) — the thousand-year-old State whose end the capture of Rome marks.
• The First Vatican Council (1869-1870) — pontifical infallibility defined at the very moment temporal power was lost.
• Blessed Pope Pius IX (1792-1878) — the pope of the Syllabus, of the last temporal power and of the "Vatican prison."
• Papal Infallibility — the dogma defined by Pastor Aeternus on 18 July 1870.
• The Lateran Agreements (11 February 1929) — the resolution of the Roman Question and the birth of Vatican City State.
• The Fall of Constantinople (29 May 1453) — another great territorial loss of Christendom, meditated upon as a providential trial.