Monte Compatri was formed at the time of the Barbarian invasions, when the inhabitants of Latina Valley sought refuge in the strongholds in the hills. Perhaps here was the ancient Latin city of Labicum destroyed by the Romans in 418 BC.

The ‘Castrum Montis Compatris’ is mentioned for the first time in the records of the Abbey of Subiaco in 1090 AD. According to tradition, in 1222 St. Francis passed here and lived in a cave nearby where the Hermitage was erected.

The town was expanded by the Counts of Tusculum, who sold it to the Annibaldi, and in 1423 it passed to the Colonna. In 1575 it was bought by Cardinal Marco Altemps for 34,000 crowns and the beginning of the following century it became property of the Borghese.

The name may derive from ‘compater’ – friend or “compitum” – road junction.