Monte Porzio Catone is a comune (municipality) in the Metropolitan City of Rome in the central Italian region of Latium, located about 20 kilometres (12 mi) southeast of Rome, on the Alban Hills.
Monte Porzio Catone borders the following municipalities: Frascati, Grottaferrata, Monte Compatri and Rome.
The Battle of Lake Regillus was a legendary Roman victory over the Latin League shortly after the establishment of the Roman Republic and as part of a wider Latin War. The Latins were led by an elderly Lucius Tarquinius Superbus, the seventh and last King of Rome, who had been expelled in 509 BC, and his son-in-law, Octavius Mamilius, the dictator of Tusculum. The battle marked the final attempt of the Tarquins to reclaim their throne. According to legend, Castor and Pollux fought on the side of the Romans.
Regillus was an ancient lake of Latium, Italy, famous in the legendary history of Rome as the lake near which the Battle of Lake Regillus took place in 496 B.C. between the Romans and the Latins which finally decided the hegemony of Rome in Latium. The lake, now drained, was near the present-day town of Frascati.
During the battle, so the story runs, the Roman dictator Postumius vowed to build a temple to the twin gods Castor and Pollux, who were specially venerated in Tusculum, the chief city of the Latins (it being a Roman custom to invoke the aid of the gods of the enemy). The pair duly appeared during the battle dressed in white armour riding white horses, helped the Romans to prevail, and afterwards took the news of the victory to Rome. There they watered their horses at the spring of Juturna, close to which their temple in the Forum was subsequently erected.