1. The causes

The Third Mithridatic War has its roots in the Peace of Dardanus that was never ratified. When a Pontic delegation arrived in Rome in 78 BC to do so, it was rebuffed. Both sides knew this would eventually lead to war and Mithridates VI immediately began to overhaul and augment his forces. By 75 BC a casus belli was at hand. Mithridates laid claim to Bithynia even though its childless king had decided to bequeath it to Rome. A clash between the two sides became inevitable and when the king of Bithynia died early in 74 BC Mithridates invaded and overwhelmed the small Roman force which had occupied the area. The command against the king of Pontus was given in that same year to general Lucullus together with the provinces of Asia and Cilicia. He had as his co-commander C. Aurelius Cotta who shared the consulship with him in that year.

2. The events

2.1. Lucullus against Mithridates VI

Lucullus’ first act on reaching Asia was to assist his colleague C. Aurelius Cotta at a siege at Chalcedon in Bithynia (Üsküdar) by Mithridates VI. The king then put Cyzicus (Kapıdağı) under siege but was in turn besieged by Lucullus who forced him to flee early in 73 BC. The remaining Pontic garrisons were then cleared from Asia and the grip of the Pontic navy on the Aegean was broken. The invasion of the Kingdom of Pontus followed. The year 72 BC was spent in pursuing Mithridates and, although Lucullus managed to defeat him at Cabira (Niksar) in Pontus, the king proved elusive finally taking refuge 71 BC with his son-in-law Tigranes I of Armenia.

Most of 70 BC was taken up by Lucullus’ administration of Asia. He levied taxes to pay for the province’s defence but more notably he introduced several measures to relieve the debt crisis of the cities. To meet the financial penalties Sulla had imposed on them, these cities had borrowed heavily and were now in debt to the Roman publicans (moneylenders). The measures of Lucullus were salutary and the debt was cleared within four years. In 69 BC, when Tigranes would not yield Mithridates, Lucullus invaded Armenia and destroyed its capital Tigranocerta (Sivan).

After this Lucullus’ fortune steadily deteriorated. His reforms in Asia had alienated the publicans, who had now contrived a way to have Asia and Cilicia removed from his command. Nevertheless, Lucullus soldiered on in Armenia only to witness a resurgence in the fortunes of Mithridates and the onset of mutiny in his own army who resented the long campaigns. Mithridates defeated Lucullus’ legate at Zela in 67 BC. Full mutiny followed later in 67 BC and at the same time the remaining provinces of Lucullus, Bithynia and Pontus, were taken from him. Finally, the lex Manilia of 66 BC deprived him of his command which passed on to Pompey.

2.2. Pompey against Mithridates VI

Pompey had just defeated the pirates and was in Cilicia (66 BC) when news came that the lex Manilia had given him the command against Mithridates instead of Lucullus. Mithridates’ response to this news was to propose a truce but the terms proposed by Pompey proved unacceptable. The king therefore withdrew into the interior of his kingdom. He managed to escape a siege at Dasteina (Pürk) but was subsequently defeated at the Belgazi gorge.

At this point Mithridates was abandoned by his erstwhile ally Tigranes, King of Armenia, not to mention that the Parthians also began negotiating with Pompey. He was obliged therefore to flee to Colchis. Pompey sent a force in pursuit but himself turned into Armenia. He overthrew Tigranes but then restored him to his kingdom as a friend and ally of Rome. The Romans then (Dec. 66 BC) wintered on the banks of the river Cyrnus, where an attack by the neighbouring Albanians was repulsed and they were obliged to surrender.

The nearby Iberians first made an insincere parley as a preliminary to an attack but they were anticipated by Pompey who defeated them in the spring of 65 BC near the river Pelorus and they too eventually came to terms. A Roman incursion into Colchis itself followed but Mithridates continued to be elusive and Pompey, returning to deal with a rebellion in Albania,¹ left the Roman fleet blockading the Black Sea ports. The Albani were dealt within a battle at the river Abas. The rest of the year was devoted to stabilising relations with tribes of the Caucasus and the Caspian. There were also negotiations with the Parthians who had established treaties with Rome since the time of Sulla but were now worried about Pompey’s growing power and his attitude towards Armenia. Pompey then withdrew from Albania and spent the winter of 65-64 BC in lesser Armenia where he captured a number of fortresses belonging to Mithridates.

In early 64 BC Pompey moved to Amisus where he began the process of making arrangements for the administration of the east. From there he began to make his way towards Syria and Arabia where his legates had already been operating. He crossed the Halys into Cappadocia. Then after a visit to Commagene and Cilicia, Pompey passed into Syria. At Antioch most of his time was consumed with administration. Moving on to Damascus he intervened in the Jewish civil war. Both protagonists, Aristobulus and Hyrcinus presented themselves to him. The matter was not resolved however and Pompey laid siege to Aristobulus in Jerusalem. The fall of the city brought the war to an end. Prior to that, however, news had come that Mithridates, desparate for further resistance, had committed suicide. Pompey hurried to Amisus to view the embalmed body and complete his administrative arrangements. Thus, having his mission accomplished, he returned to Rome in 62 BC.

3. The result

The end of this war was the epilogue of almost forty years of confrontation between Mithridates and Rome. Another lasting effect was Pompey’s settlement of the East which endured for centuries.