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
When the suppression of the Cinnan revolution, which threatened
the very existence of the senate, rendered it possible for the restored
senatorial government to devote once more the requisite attention
to the internal and external security of the empire, there emerged
affairs enough, the settlement of which could not be postponed
without injuring the most important interests and allowing
present inconveniences to grow into future dangers. Apart from
the very serious complications in Spain, it was absolutely necessary
effectually to check the barbarians in Thrace and the regions
of the Danube, whom Sulla on his march through Macedonia had only
been able superficially to chastise,(1) and to regulate, by military
intervention, the disorderly state of things along the northern
frontier of the Greek peninsula; thoroughly to suppress
the bands of pirates infesting the seas everywhere, but especially
the eastern waters; and lastly to introduce better order
into the unsettled relations of Asia Minor.