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
Amalgamation of the Palatine and Quirinal Cities
The history of every nation, and of Italy more especially, is a συνοικισμός on a great scale. Rome, in the earliest form in which we have any knowledge of it, was already triune, and similar incorporations only ceased when the spirit of Roman vigour had wholly died away. Apart from that primitive process of amalgamation of the Ramnes, Titles, and Luceres, of which hardly anything beyond the bare fact is known, the earliest act of incorporation of this sort was that by which the Hill-burgesses became merged in the Palatine Rome. The organization of the two communities, when they were about to be amalgamated, may be conceived to have been substantially similar; and in solving the problem of union they would have to choose between the alternatives of retaining duplicate institutions or of abolishing one set of these and extending the other to the whole united community.
They adopted the former course with respect to all sanctuaries and priesthoods. Thenceforth the Roman community had its two guilds of Salii and two of Luperci, and as it had two forms of Mars, it had also two priests for that divinity--the Palatine priest, who afterwards usually took the designation of priest of Mars, and the Colline, who was termed priest of Quirinus. It is likely, although it can no longer be proved, that all the old Latin priesthoods of Rome--the Augurs, Pontifices, Vestals, and Fetials--originated in the same way from a combination of the priestly colleges of the Palatine and Quirinal communities. In the division into local regions the town on the Quirinal hill was added as a fourth region to the three belonging to the Palatine city, viz. the Suburan, Palatine, and suburban (-Esquiliae-).
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