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
Siege and Battle of Tigranocerta
The exhaustless showers of arrows which the garrison poured upon the Roman army, and the setting fire to the besieging machines by means of naphtha, initiated the Romans into the new dangers of Iranian warfare; and the brave commandant Mancaeus maintained the city, till at length the great royal army of relief had assembled from all parts of the vast empire and the adjoining countries that were open to Armenian recruiting officers, and had advanced through the north-eastern passes to the relief of the capital. The leader Taxiles, experienced in the wars of Mithradates, advised Tigranes to avoid a battle, and to surround and starve out the small Roman army by means of his cavalry.
But when the king saw the Roman general, who had determined to give battle without raising the siege, move out with not much more than 10,000 men against a force twenty times superior, and boldly cross the river which separated the two armies; when he surveyed on the one side this little band, "too many for an embassy, too few for an army," and on the other side his own immense host, in which the peoples from the Black Sea and the Caspian met with those of the Mediterranean and of the Persian Gulf, in which the dreaded iron-clad lancers alone were more numerous than the whole army of Lucullus, and in which even infantry armed after the Roman fashion were not wanting; he resolved promptly to accept the battle desired by the enemy.
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=45