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
A different course was adopted with the region on the south of the Po,
which the Roman senate had determined to incorporate with Italy. The
Boii, who were immediately affected by this step, defended themselves
with the resolution of despair. They even crossed the Po and made an
attempt to rouse the Insubres once more to arms (560); they blockaded
a consul in his camp, and he was on the point of succumbing; Placentia
maintained itself with difficulty against the constant assaults of
the exasperated natives.
At length the last battle was fought at
Mutina; it was long and bloody, but the Romans conquered (561);
and thenceforth the struggle was no longer a war, but a slave-hunt.
The Roman camp soon was the only asylum in the Boian territory;
thither the better part of the still surviving population began to
take refuge; and the victors were able, without much exaggeration, to
report to Rome that nothing remained of the nation of the Boii but old
men and children.