The Battle of Monte Marrone on 31 March 1944 is a crucial military episode in the definition of the conflict between the Allies and the Germans along the Gustav Line. By conquering the summit of the Mainarde massif, the Allies were able to easily move towards the town of Cassino, whose liberation paved the way for the reconquest of the Italian capital.

The military operation was planned and entirely carried out by Italian troops. Given the stalemate in the conflict, partly due to the dreaded impregnability of Monte Marrone's peak, which was permanently garrisoned by Nazi soldiers, General Umberto Utili drew up an operational plan aimed at achieving the surprise effect. The First Motorised Regiment stationed in the upper Volturno valley was reinforced in mid-March 1943 by the entry into its ranks of the Alpine Battalion Piedmont from Apulia. Then, in view of the experience of the Alpine troops, Utili developed the new strategy of assaulting the enemy-held peak. The general planned to climb the rock faces during the night in order to take the German troops by surprise. The operation authorised by the Allied command was carried out by the Alpine soldiers of the Piemonte Battalion from the early morning hours of 31 March 1944. In just a few hours, the Alpine troops covered a distance of around 700 metres in total darkness, reaching the peak at around 6.00 a.m. and taking the Nazis by surprise, forcing them to surrender. The battle was minor and resulted in no major damage. However, an important step in the advance of the Allied armies towards the nerve centre of Cassino, whose liberation eventually led directly to Rome, was the conquest of Monte Marrone.

Furthermore, the Battle certified the contribution of the Italian army, whose contribution was also recognised by the Supreme Allied Command, which approved the establishment of a new unit to replace the First Motorised Regiment. The Italian Liberation Corps was established on the Molise side of the Mainarde mountains. It was an entity comprising all Italian soldiers involved in the campaign to liberate the country from Nazi-fascism.