[4] Mithridates entertained ambitions of making his state the dominant power in the east of Asia Minor and the Black Sea region.

The most important cities and people of the Crimea, the Tauric Chersonesus and the Bosporan Kingdom readily surrendered their independence in return for Mithridates' protection against the Scythians, their ancient enemies.

The Scythians and their allies the Rhoxolanoi suffered heavy losses at the hands of the Pontic general Diophantus and accepted Mithridates as their overlord.

When Mithridates fell out with Nicomedes over control of Cappadocia, and defeated him in a series of battles, the latter was constrained to openly enlist the assistance of Rome.

The Romans twice interfered in the conflict on behalf of Nicomedes (95–92 BC), leaving Mithridates, should he wish to continue the expansion of his kingdom, with little choice other than to engage in a future Roman-Pontic war.

Mithridates plotted to overthrow him, but his attempts failed and Nicomedes IV, instigated by his Roman advisors, declared war on Pontus.

The Romans therefore mustered a great number of Asian levies and combined with Nicomedes' army they invaded Mithridates' kingdom in 89 BC.

After being victorious in several battles Sulla, being declared an outlaw by his political opponents in Rome, hurriedly concluded peace talks with Mithridates.

[9] Having launched an attack at the same time as a revolt by Sertorius swept through the Spanish provinces, Mithridates was initially virtually unopposed.

The Senate responded by sending the consuls Lucius Licinius Lucullus and Marcus Aurelius Cotta to deal with the Pontic threat.

The only other possible general for such an important command, Pompey, was in Hispania to help Metellus Pius crush the revolt led by Sertorius.

Only nearby Cyzicus held to the Roman cause, probably because many of its citizens (serving in Cotta's army as auxiliaries) had died fighting against Mithridates at Chalcedon.

The arrival of an omen, as reported by Plutarch, was thus fortuitous:[17] But presently, as they were on the point of joining battle, with no apparent change of weather, but all on a sudden, the sky burst asunder, and a huge, flame-like body was seen to fall between the two armies.

Along with Mithridates's admirals Alexandros the Paphlagonian and Dionysios Eunuchos ("the Eunuch"), he was placed in joint command of 50 ships and 10,000 handpicked men, among them, in the words of Mommsen, "the flower of the Roman emigrants.

[25] While Lucullus and Cotta prepared to invade Pontus, Mithridates gained control of the strategically important city of Heraclea Pontica and garrisoned it with 4,000 men.

[27] In 72 BC, while Cotta moved against Heraclea and Triarius managed naval affairs, Lucullus marched his army through Galatia and into Pontus.

One of those supply convoys, escorted by no less than ten cohorts of infantry (3,000–5,000 men), under the command of the legate Sornatius was attacked by the Pontic cavalry.

[33] After reducing the Pontic coast, Cotta began besieging Heraclea itself, which took him two years to complete, sacking the city in 71 BC.

Lucullus took over from Murena and proved his tactical genius once again by launching an attack at precisely the right time (when Callimachus let his defenders take a rest) and took Amisus, but not without regret; his soldiers ransacked the city and turned it into a ruin.

Lucullus, a great admirer of Greek culture, lamented that Sulla had been blessed because he was able to save Athens, while the gods had ordained the fate of Lucius Mummius Achaicus, the destroyer of Corinth, for him.

[40] In the spring of 69 BC Lucullus marched his army from Cappadocia across the Euphrates into Greater Armenia (the Armenian Empire's heartland) and the Roman-Armenian War began.

During the winter of 69–68 BC both sides opened negotiations with the Parthian king, Arsaces XVI, who was presently defending himself against a major onslaught from his rival Phraates III coming from Bactria and the far east.

[46][47][48] Soon he left this campaign, and when winter came on early in the Armenian tablelands, his troops mutinied, refusing to go further, and he was forced to withdraw southwards back into Arzenene.

But in the winter of 68/67 BC, during a terrible storm – when the defenders relaxed their guard – Lucullus launched a surprise attack and captured the city and its treasury.

The legate Gaius Valerius Triarius who was nearby bringing two legions to reinforce Lucullus took command of all Roman forces in Pontus.

[citation needed] Early in 66 the tribune Gaius Manilius proposed that Pompey should assume supreme command of the war against Mithridates and Tigranes.

He should take control from the provincial governors in Asia Minor, have the power to appoint legates himself and the authority to make war and peace and to conclude treaties on his own discretion.

[citation needed] In 65 BC, Pompey had set out in pursuit of Mithridates, meeting opposition from the Albanians who tried to overrun his camps and the Iberians whom he defeated at the battle of the Pelorus.

His eldest son, Machares, now king of Cimmerian Bosporus, whose kingdom had been reorganized by the Romans, was unwilling to aid his father.

His younger son, Pharnaces II, backed by a disgruntled and war weary populace, led a rebellion against his father.