The war against
Mithridates VI, king of
Pontus, had now lasted for almost twenty-five years (since 89 BC). Both
Lucius Cornelius Sulla Felix and
Lucius Licinius Lucullus had fought against him, achieving numerous successes. However, Lucullus' fortune and consensus among his troops had been wavering for too long, so much so that certain complaints about the recent military campaigns conducted in the East, without prior support from the Senate, also reached
Rome, where it was decided to replace the Roman proconsul in command of his province, and to send a large part of his soldiers on leave. Lucullus thus found himself exonerated, for having dissatisfied not only his troops, but also for having antagonized the powerful faction of usurers and tax collectors in
Asia. Meanwhile,
Tigranes had retreated within his kingdom, reconquering some previously lost parts. while Mithridates also hastened to reconquer part of the ancient territories of Pontus and
Lesser Armenia. Lucullus, who had initially attempted to follow him, was forced to turn back due to lack of supplies. Then it was Mithridates who counterattacked the
Romans, even managing to kill many of them in battle. First he went against a legate of Lucullus, named Fabius, who was almost massacred together with his army, if during the battle Mithridates had not been hit by a stone on the knee and by a dart under his eye, forcing the king himself to move away from the battlefield and suspend the fighting, thus allowing Fabius and the Romans to save themselves. Then Fabius was closed and besieged in
Cabira and freed only thanks to the intervention of a second legate,
Gaius Valerius Triarius, who happened to be in those parts on his march from Asia towards Lucullus. Therefore, it was the turn of Lucullus' second legate, Triarius, who had come to the aid of Fabius with his army. Triarius, determined to pursue Mithridates, managed to beat the sovereign of Pontus during this first clash, near
Comana. Then came winter, which interrupted all military operations on both sides. Once the winter had passed, Mithridates clashed with Triarius again, going to camp near
Gaziura in front of the Roman legate. Mithridates tried to lure the Roman legate into battle and in the end Triarius fell into his trap and was heavily defeated near Zela. Having obtained these two victories, Mithridates retreated to the country that the Romans called little Armenia (on the hills near Talauro), destroying everything that he was not able to transport, in order to avoid being reached by Lucullus in his march. Then Mithridates decided to invade
Cappadocia again, managing to conquer almost all of its old dominions. He then proceeded to fortify his kingdom and damaged nearby Cappadocia, while the Romans did nothing, either because they were busy against the pirates of the
Mediterranean, or because neither Acilius, nor Lucullus (by now ousted from command), nor Marcius ( new governor of
Cilicia), took no action against him. While
Lucullus was occupied with
Mithridates and
Tigranes II, Gnaeus
Pompey managed to cleanse the entire Mediterranean basin from pirates, wresting from them the island of
Crete, the coasts of
Lycia,
Pamphylia, and Cilicia, demonstrating extraordinary discipline and organizational ability (in 67 BC). Cilicia proper (Trachea and Pedias), which had been a pirate den for over forty years, was thus definitively subjugated. Following these events the city of Tarsus became the capital of the entire Roman province. As many as 39 new cities were then founded. The speed of the campaign indicated that Pompey had been talented as a general at sea, with strong logistical skills. Pompey was then tasked with conducting a new war against
Mithridates VI, king of
Pontus, in the East (in 66 BC), thanks to the
lex Manilia, proposed by the plebeian tribune
Gaius Manilius, and politically supported by
Caesar and
Cicero. This command essentially entrusted him with the conquest and reorganization of the entire eastern
Mediterranean, having the power to proclaim which were the client peoples and which were the enemies, with an unlimited power never before conferred on anyone, and attributing to him all the forces military forces beyond the borders of Roman Italy. Pompey, having understood that it was necessary to continue the war against Mithriadates, made the necessary preparations, recalling the Valerian legion into service. Having arrived in
Galatia, coming from the south after crossing the "gates of Cilicia", he met
Lucullus on the way back. Meanwhile, Mithridates, since he initially had fewer armed men than Pompey, began to plunder, forcing Pompey to run after him, as well as trying in every way to block his supplies. The king of Pontus, who still had an army of 30,000 infantr and 2,000/3,000 cavalry, had positioned himself along the frontier of his kingdom, and since Lucullus had shortly before devastated that region, there were few supply resources so much so that many of its armed forces were forced to desert. The king, then, being now short of supplies, preferred to withdraw, allowing Pompey to follow him, albeit letting him enter his territories, and thus hoping that the Roman general himself could find himself in the same conditions as him due to the scarcity of supplies. But Pompey had adequately organized his supplies (also building a series of water wells), having conquered the
Armenian region of Anaitide shortly before. Pompey was thus able to continue his march passing through the eastern borders of Mithridates' kingdom, establishing a series of new fortified positions (at regular intervals of 25 km from each other). He therefore designed a circumvallation line that would allow him to besiege the king of Pontus and obtain supplies without major difficulties. The Roman general
Lucullus had led the eastern campaign from 73 BC to 67 BC but after a mutiny of his army he had retreated to
Galatia in
Asia Minor. In 66 BC, the
Roman Senate gave command of the war against Mithridates to Gnaeus Pompeius (better known as
Pompey). That same year Pompey effectively defeated
Mithridates at the
Battle of the Lycus, with the king escaping through
Colchis to the
Bosporean kingdom north of the
Black Sea. A pursuit party was sent after him, they followed him all the way to Colchis but lost his trail. Pompey meanwhile prepared to advance into Armenia against his second enemy, Tigranes II the Great king of the
Armenian empire. When he did Tigranes submitted and was allowed to keep Armenia, but not those lands he had won by conquest (parts of Cappadocia, Cilicia, Syria, Phoenicia, and Sophene). Pompey left Armenia under the military supervision of
Afranius, he sent
Gabinius south-east towards Mesopotamia and he himself marched the main army north (into the valley of the river Cyrnus) towards the Kingdom of Albania. Here he split his troops into three divisions and put them into winter quarters. ==First campaign==