MENTANA, BATTLE OF. — This battle takes its name from the locality where, on 3 Nov. 1867, at the twilight of the Papal States, there came to a close the bitter guerrilla warfare unleashed by the Garibaldians since 28 Sept. of that same year on the borders and within the territory of the surviving Patrimony of St Peter, not without covert aid from the royal government and in violation of the Convention of Sept. 1864.
The firmness of the Roman government, aided by the indifference of the local populations, by the diplomacy of Cardinal Antonelli (q.v.) and of the French chargé d’affaires Armand (q.v.), and by the effective resistance that for a month had been offered everywhere by the papal troops, organized and led by General Kanzler (q.v.), prevented the repetition of the Cavourian game of 1859–60, which Rattazzi, albeit clumsily, sought to play once more—namely, to provoke through more or less covert maneuvers by the Party of Action the hoped-for intervention by the royal forces. It finally compelled, on the one hand, the Menabrea cabinet to reveal itself by occupying certain points of the territory, and, on the other, Emperor Napoleon III to move from mere platonic protests to the dispatch of fresh troops to protect the Pope.
On the eve of the royal intervention (30 Oct.), the papal command had promptly acted in accordance with prearranged plans, initiating a broad movement along interior lines, which resulted in the concentration of all mobile forces (about 8,000 men) around Rome and Civitavecchia, both to offer a final defense and to launch an attack after the possible landing of the French. This had led to the definitive suppression of the pseudo-insurrectionary movements in Rome (22–25 Oct.), to the conclusion of the exploits of the Cairoli brothers (22–23 Oct.), and, more importantly, to the complete failure of the enemy’s final offensive. This offensive, launched by Garibaldi with 11,000 men on 23 Oct., broke against the fierce resistance of a weak papal outpost at Monterotondo (24–26 Oct.) and then petered out along the Aniene River between the Salario and Nomentano bridges (29–31 Oct.). Thus, thanks to Kanzler’s strategy, just as the French were unexpectedly landing at Civitavecchia (29–30 Oct.) and papal troops were preparing to advance toward the provinces of Frosinone and Viterbo, held by forces under Nicotera and Acerbi (31 Oct.), the center of the Garibaldian deployment was forced to fall back on Monterotondo and Mentana, a few kilometers from the border (31 Oct.–1 Nov.).
On 2 Nov., General Kanzler, who was eager to attack the main body of the enemy forces before they could slip across the border, found it no easy task to secure the cooperation of the French, who, for equally political reasons, did not wish to become deeply engaged against the Garibaldians. Only the fear that the papal forces might, if necessary, act alone induced General de Failly to abandon his stance and, the following day, to attach a French reserve of about 2,000 men to the column of some 3,000 papal troops.
Thus, shortly after midday on 3 Nov., the Franco-papal troops under Kanzler surprised the right flank of the enemy battalions (about 7,000 men), which, under Garibaldi’s command, were retreating toward Tivoli to reach Abruzzo. The papal zouaves and the external carabinieri of General de Courten (q.v.) were immediately engaged, and through repeated attacks, which the enemy sustained with great valor, they succeeded in driving them back from the strong positions of Colle Santucci and Monte Guarnieri. By two in the afternoon, the battlefront had shifted: the Garibaldians, having lost their first and second lines of resistance, were hemmed in against the village, awaiting their last stand in the Baronial Castle on the extreme right, along the road to Monterotondo on the left, holding the center at Villa Cicconetti and the Pagliai farmhouses. Once again, and at considerable cost, the papal forces, reinforced by the Roman Legion and the precise fire of their artillery, managed to envelop the enemy’s flanks and break through their center, nearly reaching the road to Palombara, seizing the Pagliai locality, and encircling Mentana in a ring of fire. It was three-thirty in the afternoon. Garibaldi, resolved to break free from the encirclement, ordered a final general pincer counterattack, clearly intending to trap the papal forces and crush them against the relentless rifle fire from the village. Kanzler was quick to react, exploiting a papal column that, advancing along the Salaria road, threatened the Garibaldians’ rear between Mentana and Monterotondo, and by deploying his forces methodically—throwing in the French reserve on the left and right against the enveloping wings while his own troops in the center pressed hard and advanced toward the inhabited area. Thus shattered was the well-conceived Garibaldian maneuver, and the outcome of the battle, which lasted until dusk, was decided: the enemy line collapsed in confusion across the entire front.
The next day, while the Franco-papal forces occupied Mentana and Monterotondo, Garibaldi withdrew with the remainder of his men across the border near Corese.
Thus was Mentana a hard-fought victory, contested with skill and valor by both sides. Among the papal and French forces, there were 133 dead and wounded, while the Garibaldians suffered no fewer than a thousand casualties; 1,398 were taken prisoner, and more than 4,000 managed to reach the territory of the Kingdom. The historical significance of the Battle of Mentana lies not only in having definitively ended the guerrilla warfare in Rome and Lazio but also, and above all, in having brought to a close in the Kingdom the now-outmoded phase of voluntaristic and pseudo-revolutionary adventures of the Left; and, finally, in having prolonged for another three years the already precarious existence of the ancient Papal State, thereby enabling Pius IX, despite the obstacles placed in his path by all the great powers, to carry forward the memorable labors of the Vatican Council.