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 Roman world of gods, as we have already indicated,(1) was a higher counterpart, an ideal reflection, of the earthly Rome, in which the little and the great were alike repeated with painstaking exactness.
1. Cf. I. II. Religion
The state and the clan, the individual phenomenon of nature as well as the individual mental operation, every man, every place and object, every act even falling within the sphere of Roman law, reappeared in the Roman world of gods; and, as earthly things come and go in perpetual flux, the circle of the gods underwent a corresponding fluctuation.
The tutelary spirit, which presided over the individual act, lasted no longer than that act itself: the tutelary spirit of the individual man lived and died with the man; and eternal duration belonged to divinities of this sort only in so far as similar acts and similarly constituted men and therefore spirits of a similar kind were ever coming into existence afresh.
As the Roman gods ruled over the Roman community, so every foreign community was presided over by its own gods; but sharp as was the distinction between the burgess and non-burgess, between the Roman and the foreign god, both foreign men and foreign divinities could be admitted by resolution of the community to the freedom of Rome, and when the citizens of a conquered city were transported to Rome, the gods of that city were also invited to take up their new abode there.
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Reference address : https://www.ellopos.net/elpenor/rome/1-12-religion.asp