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
The governor was not prepared for military measures, and even the
wretched militia of the island was not immediately at hand; so that he
concluded an alliance with one of the best known captains of banditti
in the island, and induced him by the promise of personal pardon to
betray the revolted slaves into the hands of the Romans. He thus
gained the mastery over this band. But another band of runaway
slaves succeeded in defeating a division of the garrison of Enna
(Castrogiovanni); and this first success procured for the insurgents--
what they especially needed--arms and a conflux of associates.
The armour of their fallen or fugitive opponents furnished the first
basis of their military organization, and the number of the insurgents
soon swelled to many thousands. These Syrians in a foreign land
already, like their predecessors, seemed to themselves not unworthy
to be governed by kings, as were their countrymen at home; and--
parodying the trumpery king of their native land down to the very
name--they placed the slave Salvius at their head as king Tryphon.