Leonardo tried an experimental wall-painting technique, not wanting to paint in fresco. The humidity in the room caused the paint to start flaking as soon as 1517, and by 1586 it was barely visible. After several bungled restorations, the monks decided to cut a doorway through the center of the painting in 1653, amputating the feet of Jesus and part of the table in the process.

Occupying French troops under Napoleon next used the building as a stable in 1796, and out of sheer boredom, the soldiers took turns throwing clay at the faces of the Apostles as target practise. Then, in 1800, a flood left green mold all over the face of the painting, but it was painstakingly removed.

As an industrial center, Milan was the target of continuous Allied bombing in World War Two, and on July 12, 1943, after repeated heavy bombing, 656 RAF bombers destroyed Milan within 30 minutes after dropping 1,000 tons of incendiaries (out of a total load of 1,252 tons of bombs) squarely on the city center. The wall with the painting survived only because it had been protected by sandbags. However, the bombing tore off the room’s roof, leaving the fresco exposed to the elements for three years.

The Last Supper has been extensively restored at a cost of millions of dollars, and so has Milan, which had to be completely reconstructed after the war. Leonardo did extensive research and created many studies and preparatory sketches before completing the painting, twenty of which have survived and are, oddly enough, kept in the Royal Library at Windsor Castle, where they have been stored since 1600.

In 1306, Brother Giovanni degli Eremitani, a monk famous for having built the roof of the Palace of Reason, built the original roof of the church, which was blown into pieces by the attack along with the frescoes by Guariento in the apse, and by Andrea Mantegna, N Pizolo, A.Vivarini and G. d’Alemagna in the Ovetari chapel.

As it turned out, no Germans were in the church. Although the church was restored after the war, most of these frescoes that decorated the church and others were either totally lost or severely damaged. Thousand of fragments were rescued and put into boxes. After 50 years, serious effort was made to collect and to classify the 72,500 bits and pieces, out of which only 52,000 of them were big enough to be codified. Digital technology has had some success.

It received privileged status after a 787 visit from Charlemagne, but was destroyed again in 883 by the Saracens, and destroyed again by an earthquake in 1349. Again it was rebuilt. The unlucky monastery was destroyed in an Allied bombing raid based on another faulty rumor that it was being used by the Germans. It was early morning on February 15, 1944 when the abbey of Montecassino was attacked. A small group of monks plus hundreds of refugees were in the monastery when the first cluster of 250 kg bombs fell from the first of the four formations of B-17, the Flying Fortresses ordered to destroy the monastery. Four other waves of medium-range bombers followed. 453 tons of bombs dropped, in eight waves, by 239 bombers. When it was over, several hundred refugees trapped inside the building lay dead in the rubble.

At the time, the bombing of this ancient monastery was the most impressive bombardment in history ever directed at a single building. The next day, Roosevelt opened a press conference with: “I read in the afternoon papers about the bombing of the abbey of Montecassino by our forces. In the reports it was clearly explained that the reason why it was bombed is that the Germans were using it to bombard us. It was a German stronghold, with artillery and everything necessary.” This was untrue.

It was destroyed under pressure from commander Bernard Cyril Freyberg, a former New Zealand dentist. Freyberg claimed the Germans were directing their artillery fire from the abbey and on February 12, he demanded the bombing of the monastery for reasons of “military necessity,” even threatening the withdrawal of his troops were he not contented. The Americans agreed, party because the Allied media had been hammering away suggesting that soldiers were dying because military commanders in Italy were being too soft toward the Catholic Church.

On 9 March, when the English Foreign Office asked for evidence they could provide to the Vatican as to why the monastery was destroyed, English General Henry Maitland Wilson claimed he had at least twelve pieces of “irrefutable evidence” that the monastery was used by the German military, but he wanted to keep his evidence secret to prevent the Germans from “constructing false counter evidence in consequence.” It was promised that the evidence would be given to the Vatican in due time. That time never came. There had recently been no German soldiers within the abbey or in its immediate vicinity. Later it was learned that one of the “pieces of evidence” was an intercepted and mistranslated German message that they claimed said “the division is in the monastery” when in reality it said, “the monks are in the monastery.”

Sixty years later the US and England finally admitted that the bombing of Montecassino was “a tragic error... the result of poor intelligence.” Bernard Cyril Freyberg was raised to the peerage for his acts.