MENTANA, BATTLE OF. — This locality gave its name to the engagement by which, on 3 November 1867, at the twilight of the Papal States, the bitter guerrilla war launched by the Garibaldians as early as 28 September of that same year along the borders and within the surviving patrimony of St Peter came to an end, not without covert assistance from the royal government and in violation of the Convention of September 1864.
The firmness of the Roman government, aided by the indifference of the population, by the diplomacy of Cardinal Antonelli (v.) and of the French chargé d’Armand (v.), and by the vigorous resistance which, for a month, the pontifical troops KANZLER, HORMANN (v.) had everywhere been offering, prevented Rattazzi, through ineptitude, from repeating Cavour’s game of 1859–60, consisting precisely in provoking, through the more or less ill-considered manoeuvres of the Partito d’azione, the hoped-for intervention of the monarchy. In the end, it compelled the Menabrea cabinet, on the one hand, to reveal its hand by occupying several points of the territory, and Napoleon III, on the other, to move from platonic protests to sending troops once again to protect the Pontiff.
At the prelude to the royal intervention (30 October), the pontifical command had acted promptly, according to its pre-established plans, initiating a broad movement along interior lines, which resulted in the concentration of all the mobile forces (approximately 8,000 men) around Rome and Civitavecchia, both to mount the final defence and to go over to the attack after the possible landing of the French. This led both to the definitive suppression of the pseudo-insurrectionary Roman disturbances (22–25 October) and to the epilogue of the Cairoli brothers’ exploit (22–23 October), and, even more, to the complete failure of the enemy’s final offensive, which, launched by Garibaldi with 11,000 men on 23 October, shattered itself against the fierce resistance of a weak pontifical outpost at Monterotondo (24–26 October), and then petered out along the line of the Aniene between Ponte Salario and Ponte Nomentano (29–31 October). Thus, thanks to Kanzler’s strategy, precisely while the French were unexpectedly landing at Civitavecchia (29–30 October), and pontifical forces were preparing to move towards the provinces of Frosinone and Viterbo, held by forces under Nicotera and Acerbi (31 October), the centre of the Garibaldian deployment was forced to fall back on Monterotondo and Mentana, a few kilometres from the border (31 October–1 November).
On 2 November it was not especially easy for General Kanzler, who was intent on attacking the main body of the enemy forces with his own troops before they escaped across the border, to persuade the French—as the Roman government wished for evident political reasons, while they, for equally political reasons, did not intend to commit themselves fully against the Garibaldians—to take part in some manner in the prepared and initiated counter-offensive (26 October–6 November). Only the feared realization that the pontifical forces were, if necessary, ready to act even alone induced General De Failly to abandon his attitude and to join a French reserve of approximately 2,000 men to the column of approximately 3,000 pontifical troops for the following day.
Thus, shortly after midday on 3 November, the Franco-pontifical troops commanded by Kanzler unexpectedly struck, along the Via Nomentana two kilometres from M., the right flank of the enemy battalions (approximately 7,000 men), which, under Garibaldi’s orders, were withdrawing towards Tivoli in order then to reach Abruzzo. The pontifical Zouaves and the CORTONA (v.) were immediately engaged and, through repeated attacks, which the enemy sustained with great courage, succeeded in driving them from the strong positions of Colle Santucci and Monte Guarnieri. At two in the afternoon the battlefront changed: the Garibaldians, having lost their first and second lines of resistance and pressed back against the town, took up positions in the baronial Castle on the extreme right, on the road to Monterotondo on the left, and held the centre at Villa Cicconetti and the Pagliai. But once again, albeit with considerable losses, the pontifical troops, supported by the forces of the Roman Legion and by the accurate fire of the artillery, succeeded in enveloping their wings and forcing their centre, reaching almost to the road to Palombara, seizing the Pagliai area, and closing M. within a circle of fire. It was half past three in the afternoon: Garibaldi, determined to free himself from the vise, ordered a final general pincer counter-attack, plainly intending in his turn to encircle the pontifical troops and crush them against the village’s still-active rifle fire. Kanzler was quick to react, taking advantage of a pontifical column which, coming from the Via Salaria, threatened the Garibaldians from the rear between M. and Monterotondo, and developing the action in an orderly manner by throwing the French reserve into the fray on the left and right against the enveloping arms, while his troops in the centre continued to press hard and advance towards the built-up area. With the Garibaldian manoeuvre thus broken, the outcome of the battle, which lasted until sunset, was decided: the enemy line fell back in confusion along the entire front.
The following day, while the Franco-pontifical forces occupied M. and Monterotondo, Garibaldi withdrew with the remainder of his men across the border near Corese.
Thus M. was a notable victory contested by both sides with skill and courage. Among the dead and wounded there were 133 pontifical troops and 39 Frenchmen, and no fewer than a thousand Garibaldians; another 1,398 were taken prisoner, while more than 4,000 were able to reach the territory of the Kingdom. The historical importance of the battle of M. lies not only in having definitively brought the guerrilla war in Rome and Latium to an end, but also, and above all, in having put an end once and for all within the Kingdom to the now-outmoded phase of the voluntarist and pseudo-revolutionary adventures of the Left; and finally, in having prolonged for another three years the already precarious life of the ancient Papal State, thereby allowing, among other things, Pius IX to give free rein, despite the obstacles placed in his way by all the powers, to the memorable work of the First Vatican Council.
Paolo Dalla Torre