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
Thus the
Roman government, in the plenitude of its power and during the most
profound inward and outward peace at home, had its decrees derided
by the impotent kings of the east; its name was misused, its ward
and its commissioner were murdered. Seventy years before, when
the Illyrians had in a similar way laid hands on Roman envoys,
the senate of that day had erected a monument to the victim in the
market-place, and had with an army and fleet called the murderers to
account.
The senate of this period likewise ordered a monument to be
raised to Gnaeus Octavius, as ancestral custom prescribed; but instead
of embarking troops for Syria they recognized Demetrius as king of the
land. They were forsooth now so powerful, that it seemed superfluous
to guard their own honour. In like manner not only was Cyprus
retained by Egypt in spite of the decree of the senate to the
contrary, but, when after the death of Philometor (608) Euergetes
succeeded him and so reunited the divided kingdom, the senate
allowed this also to take place without opposition.