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 German general replied to the Roman, in the full consciousness of equality of rights, that northern Gaul had become subject to him by right of war as fairly as southern Gaul to the Romans; and that, as he did not hinder the Romans from taking tribute from the Allobroges, so they should not prevent him from taxing his subjects.
In later secret overtures it appeared that the prince was well aware of the circumstances of the Romans; he mentioned the invitations which had been addressed to him from Rome to put Caesar out of the way, and offered, if Caesar would leave to him northern Gaul, to assist him in turn to obtain the sovereignty of Italy--as the party-quarrels of the Celtic nation had opened up an entrance for him into Gaul, he seemed to expect from the party- quarrels of the Italian nation the consolidation of his rule there.
For centuries no such language of power completely on a footing of equality and bluntly and carelessly expressing its independence had been held in presence of the Romans, as was now heard from the king of the German host; he summarily refused to come, when the Roman general suggested that he should appear personally before him according to the usual practice with client-princes.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/5-07-subjugation-west.asp?pg=69