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.
Third Mithridatic War (cont'd)
 Pompey himself hastened to Cilicia with forces of various kinds and many engines,note[67 BCE.] as he expected that there would be need of every kind of fighting and every kind of siege against the rock-bound citadels; but he needed nothing. The terror of his name and the greatness of his preparations had produced a panic among the robbers. They hoped that if they did not resist they might receive lenient treatment. First, those who held Cragus and Anticragus, their largest citadels, surrendered themselves, and after them the mountaineers of Cilicia, and, finally, all, one after another.
They gave up at the same time a great quantity of arms, some completed, others in the workshops; also their ships, some still on the stocks, others already afloat; also brass and iron collected for building them, and sailcloth, rope, and various kinds of materials; and finally a multitude of captives either held for ransom or chained to their tasks. Pompey burned the materials, carried away the ships, and sent the captives back to their respective countries. Many of them there found their own cenotaphs, for they were supposed to be dead.
Those pirates who had evidently fallen into this way of life not from wickedness, but from poverty consequent upon the war, Pompey settled in Mallus, Adana, and Epiphanea, or any other uninhabited or thinly peopled town in Rough Cilicia. Some of them he sent to Dyme in Achaea. Thus the war against the pirates, which it was supposed would prove very difficult, was brought to an end by Pompey in a few days. He took seventy-one ships by capture and 306 by surrender from the pirates, and 120 of their towns, castles, and other places of rendezvous. About 10,000 of the pirates were slain in battles.
 For this victory, so swiftly and unexpectedly gained, the Romans extolled Pompey beyond measure; and while he was still in Cilicianote[In 66 BCE.] they chose him commander of the war against Mithridates, giving him the same unlimited powers as before, to make war and peace as he liked, and to proclaim nations friends or enemies according to his own judgment. They gave him command of all the forces beyond the borders of Italy. All these powers had never been given to any one general before.note[By the Lex Manilia of 66 BCE. Cicero's speech for this law (Pro lege Manilia or De imperio Cn. Pompeii) survives.]
This was perhaps the reason why they gave him the title of Pompey the Great, for the Mithridatic war had been successfully prosecuted by other generals before him. He accordingly collected his army and marched to the territory of Mithridates. The latter had an army selected from his own forces, of 30,000 foot and 3,000 horse, stationed on his frontier; but since Lucullus had lately devastated that region there was a scant supply of provisions, and for this reason many of his men deserted. The deserters whom he caught he crucified, or put out their eyes, or burned them alive. But while the fear of punishment lessened the number of deserters, the scarcity of provisions weakened him.
 Mithridates sent envoys to Pompey asking on what terms he could obtain peace. Pompey replied, "By delivering up our deserters and surrendering at discretion."
When Mithridates was made acquainted with these terms he communicated them to the deserters, and when he observed their consternation he swore that on account of the cupidity of the Romans he would never make peace with them, nor would he give up anybody to them, nor would he ever do anything that was not for the common advantage of all. So spoke Mithridates.
Then Pompey placed a cavalry force in ambush, and sent forward others to harass the king's outposts openly, and ordered them to provoke the enemy and then retreat, as though vanquished. This was done until those in ambush took their enemy in the rear and put them to flight. The Romans might have broken into the enemy's camp along with the fugitives had not the king, apprehending this danger, led forward his infantry. Then the Romans retired. This was the result of the first trial of arms and cavalry engagement between Pompey and Mithridates.
 The king, being short of provisions, retreated reluctantly and allowed Pompey to enter his territory, expecting that he also would suffer from scarcity when encamped in the devastated region. But Pompey had arranged to have his supplies sent after him. He passed around to the eastward of Mithridates, established a series of fortified posts and camps extending a distance of 25 kilometers, and drew a line of circumvallation around him which made foraging still difficult for him.
The king did not oppose this work, being either afraid or mentally paralyzed, as often happens on the approach of calamity. Being again pressed for supplies he slaughtered his pack animals, keeping only his horses. When he had scarcely fifty days' provisions left he fled by night, in profound silence, by bad roads. Pompey overtook him with difficulty in the daytime and assailed his rearguard. The king's friends then urged him to prepare for battle, but he would not fight. He merely drove back the assailants with his horse and retired into the thick woods in the evening. The following day he took up a strong position defended by rocks, to which there was access by only one road, which he held with an advance guard of four cohorts. The Romans put an opposing force on guard there to prevent Mithridates from escaping.
 At daybreak both commanders put their forces under arms. The outposts began skirmishing along the defile, and some of the king's horsemen, without their horses and without orders, went to the assistance of their advance guard. A larger number of the Roman cavalry came up against them, and the horseless Mithridateans rushed back to their camp to mount their horses and thus to make themselves a more equal match for the advancing Romans.
When those who were still arming on the higher ground looked down and saw their own men running toward them with haste and outcries, but did not know the reason, they thought that they had been put to flight. They threw down their arms and fled as though their own camp had already been captured on the other side. As there was no road out of the place they fell foul of each other in the confusion, until finally they leaped down the precipices.
Thus the army of Mithridates perished through the rashness of those who caused a panic by going to the assistance of the advance guard without orders. The remainder of Pompey's task was easy, in the way of killing and capturing men not yet armed and shut up in a rocky defile. About 10,000 were slain and the camp with all its apparatus was taken.