On Regillus lacus at the beginning of the 5th century BC The decisive battle in the first Latin War of the Roman Republic took place. The exact place and year of the event are not known, and the tradition is uncertain.
Tensions between the still young Roman Republic and the neighboring towns previously dominated by monarchical Rome led to the turn of the 6th to 5th century BC. To an independent Latin society . The military decision was made around 496 BC. BC (further dates between 509 and 493 BC are suggested) on Regillus lacus , which was possibly 4 km north of today's Frascati . The Latin cavalry led by the former Roman King Lucius Tarquinius Superbus was subject to the Roman hoplite contingent . However, Rome could not completely subdue the Latins. The following peace treaty ( foedus Cassianum ) included an equal defense alliance between Rome and the Latins.
The war - like the events before and after - has only been handed down in gaps, the battle in legendary form. The Roman dictator and military leader Aulus Postumius Albus had promised the Dioscuri ( Castor and Pollux ), patron gods of horses and cavalry, who were venerated by the Latins, that they would have their own temple and cult if they sided with the Romans. The successful enticement of the enemy deity ( exoratio ) was achieved with the construction and dedication of the promised temple in 484 BC. Chr. Repaid. A popular story told of the appearance of the Dioscuri themselves in battle and shortly afterwards in the Roman Forum , where they watered their horses at the source of the Juturna ( Lacus Iuturnae ), near the later Dioscuri temple ( Aedes Castoris ), and won victory the Romans are said to have proclaimed.