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.
 The Romans decided to restore Nicomedesnote[King Nicomedes IV Philopator of Bithynia.] and Ariobarzanesnote[King Ariobarzanes I Philoromaeus of Cappadocia.] at the same time, each to his own kingdom, and sent thither for this purpose an embassy, of which Manius Aquilius was the chief, and ordered Lucius Cassius, who was in charge of the Asiatic country around Pergamon and had a small army under his command, to cooperate in their mission.
Similar orders were sent to Mithridates Eupator himself. But the latter, being angry with the Romans on account of their interference in Cappadocia, and having been recently despoiled of Phrygia by them (as narrated in my Hellenic History), did not cooperate. Nevertheless Cassius and Manius, with the army of the former, and a large force collected from the Galatians and Phrygians, restored Nicomedes to Bithynia and Ariobarzanes to Cappadocia.
They urged them at the same time, as they were neighbors of Mithridates, to make incursions into his territory and stir up a war, promising them the assistance of the Romans. Both of them hesitated to begin so important a war on their own border, because they feared the power of Mithridates.
When the ambassadors insisted, Nicomedes, who had agreed to pay a large sum of money to the generals and ambassadors for restoring him to power, which he still owed, together with other large sums which he had borrowed on interest from the Romans in his country and for which they were dunning him, made an attack reluctantly on the territory of Mithridates and plundered it as far as the city of Amastris, meeting no resistance. note[88 BCE.]Although Mithridates had his forces in readiness he retreated, because he wanted to have good and sufficient cause for war.
 Nicomedes returned with large booty and Mithridates sent Pelopidas to the Roman generals and ambassadors. He was not ignorant that they wanted to bring on a war, and that they had incited this attack upon him, but he dissembled in order to procure more and clearer causes for the coming war, for which reason he reminded them of his own and his father's friendship and alliance, in return for which Pelopidas said that Phrygia and Cappadocia had been wrested from him, of which Cappadocia had always belonged to his ancestors and had been left to him by his own father. "Phrygia," he continued, "was given to him by your own general as a reward for his victory over Aristonicus; nevertheless he paid a large sum of money to that same general for it. But now you allow Nicomedes even to close the mouth of the Euxine, and to overrun the country as far as Amastris, and you see him carrying off vast plunder with impunity. My king was not weak, he was not unprepared to defend himself, but he waited in order that you might be eye-witnesses of these transactions. Since you have seen all this, Mithridates, who is your friend and ally, calls upon you as friends and allies (for so the treaty reads) to defend us against the wrong-doing of Nicomedes, or to restrain the wrong-doer."
 When Pelopidas had finished speaking, the ambassadors of Nicomedes, who were there to answer him, said: "Mithridates plotted against Nicomedes long ago and put Socrates on the throne by force and arms, though Socrates was of a quiet disposition and thought it right that his elder brother should reign. This was the act of Mithridates to Nicomedes whom you, Romans, had established on the throne of Bithynia - a blow which was evidently aimed as much at you as at us. In like manner after you had commanded the Asiatic kings not to molest Europe, he seized the greater part of Chersonesus. Let these acts stand as examples of his arrogance, his hostility, his disobedience towards yourselves.
Look at his great preparations. He stands in complete readiness, as for a great and predetermined war, not merely with his own army, but with great force of allies, Thracians, Scythians, and many other neighboring peoples. He has formed a marriage alliance with Armenia, and has sent to Egypt and Syria to make friends with the kings of those countries. He has 300 ships of war and is still adding to the number. He has sent to Phoenicia and Egypt for naval officers and steersmen.
These things, that Mithridates is collecting in such vast quantities, are not designed for Nicomedes, nay, o Romans, but for you. He is angry with you because, when he had bought Phrygia by a corrupt bargain from one of your generals, you ordered him to give up his ill-gotten gains. He is angry on account of Cappadocia, which was given by you to Ariobarzanes. He fears your increasing power. He is making preparations under pretense that they are intended for us, but he means to attack you if he can. It will be the part of wisdom not to wait till he declares war against you, but to look at his deeds rather than his words, and not give up true and tried friends for a hypocrite who offers you the fictitious name of friendship, nor allow your decision concerning our kingdom to be annulled by one who is equally the foe of both of us."
 After the ambassadors of Nicomedes had thus spoken Pelopidas again addressed the Roman assembly, saying that if Nicomedes was complaining of bygones, he accepted the decision of the Romans, but as to present matters which were transpiring under their eyes, the ravaging of Mithridates' territory, the closing of the sea, and the carrying away of such vast plunder, there was no need of discussion or adjudication. "We call upon you, Romans, again," he said, "either to prevent such outrages, or to assist Mithridates, who is their victim, or at all events to stand aside, allow him to defend himself, and not help either party."
While Pelopidas was repeating his demand, though it had been determined by the Roman generals long before to help Nicomedes, they made a pretense of listening to the argument on the other side. Yet the words of Pelopidas and the alliance of Mithridates, which was still in force, put them to shame, and they were at a loss for some time what answer to make. Finally, after long thought, they made this artful reply, "We would not wish that Mithridates suffer harm at the hands of Nicomedes, nor can we allow war to be made against Nicomedes, because we do not think that it would be for the interest of Rome that he should be weakened."
Having delivered this response they dismissed Pelopidas from the assembly, although he wanted to show the insufficiency of their answer.
 Mithridates, having been denied justice by the Romans in this public manner, sent his son Ariarathes with a large force to seize the kingdom of Cappadocia.note[88 BCE.] Ariarathes speedily overpowered it and drove out Ariobarzanes.
Then Pelopidas returned to the Roman generals and said: "How patiently king Mithridates bore injury from you when he was deprived of Phrygia and Cappadocia not long ago you have been told already, o Romans. What injuries Nicomedes inflicted upon him you have seen - and have not heeded. And when we appealed to your friendship and alliance you answered as though we were not the accusers but the accused, saying that it would not be for your interest that harm should come to Nicomedes, as though he were the injured one.
You therefore are accountable to the Roman republic for what has taken place in Cappadocia. Mithridates has done what he has done because you disdained us and mocked us in your answers. He intends to send an embassy to your Senate to complain against you. He summons you to defend yourselves there in person in order that you may do nothing in haste, nor begin a war of such magnitude without the decree of Rome itself.
You should bear in mind that Mithridates is ruling his ancestral domain, which is 350 kilometers long, and that he has acquired many neighboring nations, the Colchians, a very warlike people, the Greeks bordering on the Euxine, and the barbarian tribes beyond them. He has allies also ready to obey his every command, Scythians, Taurians, Bastarnae, Thracians, Sarmatians, and all those who dwell in the region of the Don and Danube and the Sea of Azov. Tigranes of Armenia is his son-in-law and the Arsacid king of Parthia is his ally. He has a large number of ships, some in readiness and others building, and apparatus of all kinds in abundance.