On the day of the 16th, the hospital opened its doors to all Jews seeking shelter from the Nazi raid. Borromeo knew the hospital was sure to be searched and so he, Sacerdoti and another physician called Adriano Ossicini, came up with an ingenious plan. They decided that any Jew who came to the hospital seeking refuge would be admitted as a new patient and declared to be suffering from a highly contagious and deadly disease known as ‘Il Morbo di K’, aka Syndrome K or ‘K’ Syndrome.

Of course, this disease was not to be found in any medical textbook, as it was entirely fictitious. Ossicini had come up with its name, aptly naming the deadly disease after two very deadly men - Albert Kesserling, the German commander in charge of the Nazi troops in Rome, and the city’s SS chief of police Herbert Kappler, a man who in March 1944 would be responsible for the Ardeatine Massacre, a reprisal killing of 335 Italian civilians.

Doctors could now tell the difference between real patients and those seeking shelter. To aid in the ruse, rooms were also set up and said to contain sufferers of the infectious disease. All patients had to play their part as well and were advised to cough violently if a Nazi soldier came close.

When the Nazi’s came to search the hospital, they were warned about the highly contagious neurological illness, known as Syndrome K, whose symptoms included convulsions and paralysis and could lead to disfiguration and ultimately death. The plan worked and the soldiers dared not enter the building.

Dr Sacerdoti told the BBC in 2004, ‘The Nazi’s thought it was cancer or tuberculosis, and they fled like rabbits.’