Sant’Oreste is located north of Rome, on one of the peaks of Mount Soratte, the sacred mountain to the Etruscans who worshiped the god Soranus (black) and the Romans who built the temple of Apollo Soranus. The rites were celebrated by the families of the Hirpi Sorani who in honour of the god walked over hot coals and were exempt from military service and other obligations. When the Romans conquered these areas they built there many villas, such as the one of Sant’Oreste.
In the Middle Ages, Mount Soratte was the refuge of Pope Sylvester I to escape persecution of Constantine and this is why a monastery was built. This area was sought after by monks and hermits including Saint Nonnoso.
In the second half of 1500, this area was granted to the Farnese family and the town was embellished with churches and palaces and the town walls were renovated. In 1661 from Germany some relics of St. Nonnoso were returned and he was declared patron of the country.
During World War II, perhaps the German settled their headquarters in Monte Soratte digging a network of tunnels.