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 chief branch, however, of the Umbrian stock threw itself eastward from Sabina into the mountains of the Abruzzi, and the adjacent hill-country to the south of them. Here, as on the west coast, they occupied the mountainous districts, whose thinly scattered population gave way before the immigrants or submitted to their yoke; while in the plain along the Apulian coast the ancient native population, the Iapygians, upon the whole maintained their ground, although involved in constant feuds, especially on the northern frontier about Luceria and Arpi. When these migrations took place, cannot of course be determined; but it was presumably about the time when kings ruled in Rome.
Tradition reports that the Sabines, pressed by the Umbrians, vowed a -ver sacrum-, that is, swore that they would give up and send beyond their bounds the sons and daughters born in the year of war, so soon as these should reach maturity, that the gods might at their pleasure destroy them or bestow upon them new abodes in other lands. One band was led by the ox of Mars; these were the Safini or Samnites, who in the first instance established themselves on the mountains adjoining the river Sagrus, and at a later period proceeded to occupy the beautiful plain on the east of the Matese chain, near the sources of the Tifernus. Both in their old and in their new territory they named their place of public assembly--which in the one case was situated near Agnone, in the other near Bojano--from the ox which led them Bovianum.
A second band was led by the woodpecker of Mars; these were the Picentes, "the woodpecker-people," who took possession of what is now the March of Ancona. A third band was led by the wolf (-hirpus-) into the region of Beneventum; these were the Hirpini. In a similar manner the other small tribes branched off from the common stock--the Praetuttii near Teramo; the Vestini on the Gran Sasso; the Marrucini near Chieti; the Frentani on the frontier of Apulia; the Paeligni on the Majella mountains; and lastly the Marsi on the Fucine lake, coming in contact with the Volscians and Latins.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/1-08-umbro-sabellian-samnites.asp?pg=5