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
But, when a government cannot govern,
it ceases to be legitimate, and whoever has the power has also
the right to overthrow it. It is, no doubt, unhappily true
that an incapable and flagitious government may for a long period trample
under foot the welfare and honour of the land, before the men are
found who are able and willing to wield against that government
the formidable weapons of its own forging, and to evoke out of
the moral revolt of the good and the distress of the many the revolution
which is in such a case legitimate.
But if the game attempted
with the fortunes of nations may be a merry one and may be played
perhaps for a long time without molestation, it is a treacherous
game, which in its own time entraps the players; and no one then
blames the axe, if it is laid to the root of the tree that bears
such fruits. For the Roman oligarchy this time had now come.
The Pontic-Armenian war and the affair of the pirates became
the proximate causes of the overthrow of the Sullan constitution
and of the establishment of a revolutionary military dictatorship.