The Sangallo Fortress – as indicated by the eleventh historical plaque – was the headquarters of US OSS detachment, the American Strategic Service, which was succeeeded by the CIA (Counter Intelligence Agency). The men of the Office of Strategic Service (about 20), landed at 2 o’ clock at night on January 22nd, 1944 by Prince Barberini property, with rubber dinghies which had been left offshore by a submarine. This detachment was commanded by Captain Jones, assited by Lieutenant Alphonse Thiele, Sergeant Aliano and Sergeant Louis Michielini. They operated in pairs, without weapons, as they had to entered with the help of a patrol, mostly men of 1st Special Service Force (The Devil Brigade) which accompanied them into Germans lines at night. The OSS men remained there for four or five days disguised as peasants. At the appointed date and time, American soldiers took them back into friendly lines. They listened, observed, studied everything that was interesting to know and reported to 5th Army headquarters and 6th Corps Strategic Service Section. At the big door of entrance of the fortress, the one near the drawbridge, they had posted the OFF LIMITS sign. An armed sentinel, with an automatic rifle, had orders to shoot anyone who tried to enter or exit without permission. General Donovan, who was the commander-in-chief of the OSS, visited the fortress in March 1944. A bomb from the German railway gun fell, without exploding, down the basement where the kichen was.
