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
Extension of the Roman Territory after the Fall of Alba - Hernici - Rutulli and Volscii
The steps by which after the fall of Alba Rome--now mistress of a territory comparatively considerable, and presumably the leading power in the Latin confederacy--extended still further her direct and indirect dominion, can no longer be traced. There was no lack of feuds with the Etruscans and with the Veientes in particular, chiefly respecting the possession of Fidenae; but it does not appear that the Romans were successful in acquiring permanent mastery over that Etruscan outpost, which was situated on the Latin bank of the river not much more than five miles from Rome, or in dislodging the Veientes from that formidable basis of offensive operations.
On the other hand they maintained apparently undisputed possession of the Janiculum and of both banks of the mouth of the Tiber. As regards the Sabines and Aequi Rome appears in a more advantageous position; the connection which afterwards became so intimate with the more distant Hernici must have had at least its beginning under the monarchy, and the united Latins and Hernici enclosed on two sides and held in check their eastern neighbours. But on the south frontier the territory of the Rutuli and still more that of the Volsci were scenes of perpetual war.
The earliest extension of the Latin land took place in this direction, and it is here that we first encounter those communities founded by Rome and Latium on the enemy's soil and constituted as autonomous members of the Latin confederacy--the Latin colonies, as they were called--the oldest of which appear to reach back to the regal period. How far, however, the territory reduced under the power of the Romans extended at the close of the monarchy, can by no means be determined. Of feuds with the neighbouring Latin and Volscian communities the Roman annals of the regal period recount more than enough; but only a few detached notices, such as that perhaps of the capture of Suessa in the Pomptine plain, can be held to contain a nucleus of historical fact.
That the regal period laid not only the political foundations of Rome, but the foundations also of her external power, cannot be doubted; the position of the city of Rome as contradistinguished from, rather than forming part of, the league of Latin states is already decidedly marked at the beginning of the republic, and enables us to perceive that an energetic development of external power must have taken place in Rome during the time of the kings. Certainly great deeds, uncommon achievements have in this case passed into oblivion; but the splendour of them lingers over the regal period of Rome, especially over the royal house of the Tarquins, like a distant evening twilight in which outlines disappear.
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Reference address : https://www.ellopos.net/elpenor/rome/1-07-hegemony-rome-latium.asp?pg=13