Although only his books on the Roman Civil Wars survive in their entirety, large parts of other books have also come down to us. Fortunately, the Mithridatic Wars, about Rome's struggle with the kingdom of Pontus, belong to these better preserved parts. They are a very valuable source for the history of the Roman expansion in what is now called Turkey.
The translation was made by Horace White; notes by Jona Lendering.
First Mithridatic War (cont'd)
 When Mithridates heard of this great disaster he was astonished and terror-stricken, as was natural.note[86 BCE.] Nevertheless, he proceeded with all haste to collect a new army from all his subject nations. Thinking that certain persons would be likely to turn against him on account of his defeat, either now or later, if they should find a good chance, he arrested all suspects before the war should become sharper.
First, he put to death the tetrarchs of Galatia with their wives and children, not only those who were united with him as friends, but those who were not his subjects - all except three who escaped. Some of these he took by stratagem, the others he slew one night at a banquet. He believed that none of them would be faithful to him if Sulla should come near. He confiscated their property, established garrisons in their towns, and appointed Eumachus satrap of the nation. But the tetrarchs who had escaped raised an army from the country people forthwith, expelled him and his garrisons, and drove them out of Galatia, so that Mithridates had nothing left of that country except the money he had seized.
Being angry with the inhabitants of Chios, one of whose vessels had accidentally run against the royal ship in the naval battle near Rhodes, he first confiscated the goods of all Chians who had fled to Sulla, and then sent persons to inquire what property in Chios belonged to Romans. For a third move, his general, Zenobius, who was conducting an army to Greece, seized the walls of Chios and all the fortified places by night, stationed guards at the gates, and made proclamation that all strangers should remain quiet, and that the Chians should repair to the assembly so that he might give them a message from the king. When they had come together he said that the king was suspicious of the city on account of the Roman faction in it, but that he would be satisfied if they would deliver up their arms and give the children of their principal families as hostages. Seeing that their city was already in his hands they gave both. Zenobius sent them to Erythrae and told the Chians that the king would write to them directly.
 A letter came from Mithridates of the following tenor: "You favor the Romans even now, and many of your citizens are still sojourning with them. You are reaping the fruits of Roman property of which you do not make returns to us. Your trireme ran against and shook my ship in the battle before Rhodes. I willingly imputed that fault to the pilots alone, hoping that you would observe the rules of safety and remain my submissive subjects. Now you have secretly sent your chief men to Sulla, and you have never proved or declared that this was done without public authority, as was the duty of those who were not cooperating with them. Although my friends consider that those who conspire against my government, and who intend to conspire against my person, ought to suffer death, I will let you off with a fine of 2,000 talents."
Such was the purport of the letter. The Chians wanted to send legates to the king, but Zenobius would not allow it. As they were disarmed and had given up the children of their principal families, and a large barbarian army was in possession of the city, they groaned aloud, but they collected the temple ornaments and the women's jewelry to the full amount of 2,000 talents.
When this sum had been made up Zenobius accused them of giving him short weight and summoned them to the theater. Then he stationed his army with drawn swords around the theater itself and along the streets leading from it to the sea. Then he led the Chians one by one out of the theater and put them in ships, the men separate from the women and children, and all treated with indignity by their barbarian captors. In this way they were dragged to Mithridates, who packed them off to Pontus on the Euxine. Such was the calamity that befell the citizens of Chios.
 When Zenobius approached Ephesus with his army, the citizens ordered him to leave his arms at the gates and come in with only a few attendants. He obeyed the order and made a visit to Philopoemen (the father of Monima, the favorite wife of Mithridates), whom the latter had appointed overseer of Ephesus, and summoned the Ephesians to the assembly.
They expected nothing good from him, and adjourned the meeting till the next day. During the night, however, they met for mutual consultation and encouragement, after which they cast Zenobius into prison and put him to death. They then manned the walls, put the citizens in training, brought in supplies from the country, and put the city in a state of complete defense.
When the people of Tralles, Hypaepa, Metropolis, and several other towns heard of this they feared lest they should meet the fate of Chios, and followed the example of Ephesus. Mithridates sent an army against the revolters and inflicted terrible punishments on those whom he captured, but as he feared other defections, he gave freedom to the Greek cities, proclaimed the canceling of debts, gave the right of citizenship to all sojourners therein, and freed the slaves. He did this hoping (as indeed it turned out) that the debtors, sojourners, and slaves would consider their new privileges secure only under the rule of Mithridates, and would therefore be well disposed toward him.
In the meantime Mynnio and Philotimus of Smyrna, Clisthenes and Asclepiodotus of Lesbos, all of them the king's intimates (Asclepiodotus had once entertained him as a guest) joined in a conspiracy against Mithridates. Of this conspiracy Asclepiodotus himself became the informer, and in order to confirm his story he arranged that the king should conceal himself under a couch and hear what Mynnio said. The plot being thus revealed the conspirators were put to death with torture, and many others suffered from suspicion of similar designs. Thus eighty citizens of Pergamon were caught taking counsel together to like purpose, and others in other cities.
The king sent spies everywhere who denounced their own enemies, and in this way about 1,500 men lost their lives. Some of these accusers were captured by Sulla a little later and put to death, others committed suicide, and still others took refuge with Mithridates himself in Pontus.
 While these events were taking place in Asia, Mithridates assembled an army of 80,000 men, which Dorylaus led to Archelaus in Greece, who still had 10,000 of his former force remaining. Sulla had taken a position against Archelaus near Orchomenus. When he saw the great number of the enemy's horse coming up, he dug a number of ditches through the plain ten feet wide, and drew up his army to meet Archelaus when the latter advanced.
The Romans fought badly because they were in terror of the enemy's cavalry. Sulla rode hither and thither a long time, encouraging and threatening his men. Failing to bring them up to their duty in this way, he leaped from his horse, seized a standard, ran out between the two armies with his shield-bearers, exclaiming, "If you are ever asked, Romans, where you abandoned Sulla, your general, say that it was at the battle of Orchomenus."
When the officers saw his peril they darted from their own ranks to his aid, and the troops, moved by the sense of shame, followed and drove the enemy back in their turn. This was the beginning of the victory. Sulla again leaped upon his horse and rode among his troops praising and encouraging them until the end of the battle. The enemy lost 15,000 men, about 10,000 of whom were cavalry, and among them Diogenes, the son of Archelaus. The infantry fled to their camps.
 Sulla feared lest Archelaus should escape him again, because he had no ships, and take refuge in Chalcis as before. Accordingly he stationed night watchmen at intervals over the whole plain, and the next day he enclosed Archelaus with a ditch at a distance of less than 600 feet from his camp, to prevent his escape. Then he appealed to his army to finish the small remainder of the war, since the enemy were no longer even making show of resistance; and so he led them against the camp of Archelaus.
Like scenes transpired among the enemy, with a change of feeling necessarily, the officers hurrying hither and thither, representing the imminent danger, and upbraiding the men if they should not be able to defend the camp against assailants inferior in numbers. There was a rush and a shout on each side, followed by many valiant deeds on the part of both. The Romans, protected by their shields, were demolishing a certain angle of the camp when the barbarians leaped down from the parapet inside and took their stand around this corner with drawn swords to ward off the invaders.
No one dared to enter until the military tribune, Basillus, first leaped over and killed the man in front of him. Then the whole army dashed after him. The flight and slaughter of the barbarians followed. Some were captured and others driven into the neighboring lake, and, not knowing how to swim, perished while begging for mercy in barbarian speech, not understood by their slayers. Archelaus hid in a marsh, where he found a small boat by which he reached Chalcis. Whatever remained of the Mithridatean forces in separate detachments he summoned thither with all speed.