Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
The Hegemony of Rome over Latium Shaken and Re-established
The great achievement of the regal period was the establishment of the sovereignty of Rome over Latium under the form of hegemony. It is in the nature of the case evident that the change in the constitution of Rome could not but powerfully affect both the relations of the Roman state towards Latium and the internal organization of the Latin communities themselves; and that it did so, is obvious from tradition.
The fluctuations which the revolution in Rome occasioned in the Romano-Latin confederacy are attested by the legend, unusually vivid and various in its hues, of the victory at the lake Regillus, which the dictator or consul Aulus Postumius (255? 258?) is said to have gained over the Latins with the help of the Dioscuri, and still more definitely by the renewal of the perpetual league between Rome and Latium by Spurius Cassius in his second consulate (261).
These narratives, however, give us no information as to the main matter, the legal relation between the new Roman republic and the Latin confederacy; and what from other sources we learn regarding that relation comes to us without date, and can only be inserted here with an approximation to probability.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/2-05-subjugation-latins-campanians.asp