San Polo Dei Cavalieri is situated on a hill at the foot of Mount Morra and Monte Gennaro, in the heart of the Lucretili Mountains Park east of Rome, along the Via Tiburtina Valeria. Its history is linked to its geographical position of control and it marked a boundary between the dominion of the Abbey of St. Paul Outside the Walls and that of the Tivoli.
In 1029, the abbey of St. Paul Outside the Walls started the construction of a ‘castrum’ with a tower, probably above a previous Roman building. This original castle was long contested until in 1390 Pope Boniface IX gave it to the Orsini who transformed it into a veritable fortress.
The name of San Paolo Die Cavalieri certainly comes from Sao Paulo but it is uncertain the story of the second part on which there are many legends. In some documents appears in St. Paul Jana, which would connect to the god Jano or Mount Gennaro, others simply claim that the name takes the family Dei Cavalieri with which the Orsini were related.