While the Allies advanced towards Cassino, a German stronghold, two officers of the Hermann Göring Panzer Division, Captain Maximilian Becker and Lieutenant Colonel Julius Schlegel, proposed to transfer the treasures of Montecassino to the Vatican and to Castel Sant’Angelo, also owned by the Vatican, before the front approached. The officers convinced the Church authorities and their own superiors to use the trucks of the division and the gas for the journey. They had to procure the material necessary to create boxes built by the carpenter’s soldiers and recruit local workers (who were paid with food rations and twenty cigarettes a day). Finally, they organized “the great evacuation of the library and the archives”, a treasure literally priceless.

Montecassino and the Gustav Line were attacked 4 times by the Allies, including the last attack involving twenty divisions that bombed along a front of twenty miles.

Montecassino, the historic Abbey on the mountain founded by St. Benedict of Nusia in 529 AD, dominated the underlying city of Cassino and the entrances to the valleys of the Liri and Rapido river.

Being in a historically protected area, it was not occupied by the Germans even though they sought strategic positions a few steps from the Abbey in the valleys below. Due to repeated artillery attacks by Allied assault troops, the leaders of the latter came to the conclusion that the Abbey was used by the Germans, at least as an observation point. The fear increased due to the increasing number of deaths and although in the absence of concrete evidence, the destruction of the Abbey was decided.

At dawn on the day after the bombing, many of the surviving civilians fled from the ruins. Only 40 people remained: the six monks who had survived in the deep vaults of the Abbey, the seventy-nine-year-old abbot, Bishop Gregorio Diamare, three peasant families, orphaned and abandoned children, the mortally wounded and the dying. After the destruction, new attacks and bombings by the 4th Indian Division, the monks decided to abandon their devastated home at 5.30pm on February 17th.

On the 17th of May, the Polish Corps unleashed the second attack on Montecassino. Under constant artillery shells and mortar shells from the fortified positions of the Germans and with natural coverings as protection, the fight was hard and sometimes even hand-to-hand. Aware that their line was threatened by the Allied advance in the Liri Valley, the Germans decided to withdraw from the heights of Cassino to the new defensive positions in the Hitler Line.

In the early hours of May 18, the 78th British Division and the Polish Corps reached the Liri Valley two miles (3.2 km) west of Cassino. Here, the survivors of the second Polish offensive were so weak that it took time to find men strong enough to climb the last 100 meters to the top. A Polish patrol of the 12th Cavalry Regiment eventually reached the summit and raised the Polish flag among the ruins. The only remaining defenders were a group of thirty wounded Germans who were unable to escape. At the end of the war a Polish cemetery was built in Montecassino, on the slope of the mountain.