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
Inroad of the Helvetii into Southern Gaul - Defeat of Longinus
Thus the Roman province and the new Roman army were left for the moment undisturbed by the Germans; but a new enemy arose in Gaul itself. The Helvetii, who had suffered much in the constant conflicts with their north-eastern neighbours, felt themselves stimulated by the example of the Cimbri to seek in their turn for more quiet and fertile settlements in western Gaul, and had perhaps, even when the Cimbrian hosts marched through their land, formed an alliance with them for that purpose.
Now under the leadership of Divico the forces of the Tougeni (position unknown) and of the Tigorini (on the lake of Murten) crossed the Jura,(20) and reached the territory of the Nitiobroges (about Agen on the Garonne).
20. The usual hypothesis, that the Tougeni and Tigorini had advanced at the same time with the Cimbri into Gaul, cannot be supported by Strabo (vii. 293), and is little in harmony with the separate part acted by the Helvetii. Our traditional accounts of this war are, besides, so fragmentary that, just as in the case of the Samnite wars, a connected historical narration can only lay claim to approximate accuracy.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/4-05-peoples-north.asp?pg=32