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
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
From far and near the Asiatics flocked in crowds to the banner of the kings, who summoned them to protect the east and its gods from the impious foreigners. But facts had shown not only that the mere assemblage of enormous hosts was of little avail, but that the troops really capable of marching and fighting were by their very incorporation in such a mass rendered useless and involved in the general ruin. Mithradates sought above all to develop the arm which was at once weakest among the Occidentals and strongest among the Asiatics, the cavalry; in the army newly formed by him half of the force was mounted. For the ranks of the infantry he carefully selected, out of the mass of recruits called forth or volunteering, those fit for service, and caused them to be drilled by his Pontic officers.
The considerable army, however, which soon assembled under the banner of the great- king was destined not to measure its strength with the Roman veterans on the first chance field of battle, but to confine itself to defence and petty warfare. Mithradates had conducted the last war in his empire on the system of constantly retreating and avoiding battle; similar tactics were adopted on this occasion, and Armenia proper was destined as the theatre of war--the hereditary land of Tigranes, still wholly untouched by the enemy, and excellently adapted for this sort of warfare both by its physical character and by the patriotism of its inhabitants.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/5-02-rule-sullan-restoration.asp?pg=52