Such was the state of affairs when ten legates arrived in Asia to reduce Pontus to the form of a Roman province, and they had, in consequence, to report to the Senate that the country supposed to be conquered was again in the hands of the enemy. The adversaries of Lucullus naturally availed themselves of so favorable an occasion, and a decree was passed transferring to M. Acilius Glabrio, one of the Consuls for the year, the province of Bithynia, and the command against Mithridates. But Glabrio was wholly incompetent for the task assigned to him. On arriving in Bithynia he made no attempt to assume the command, but remained within the confines of his province, while he still farther embarrassed the position of Lucullus by issuing proclamations to his soldiers, announcing to them that their general was superseded, and releasing them from their obedience. Before the close of the year (B.C. 67) Lucullus had the mortification of seeing Mithridates established once more in the possession of his hereditary dominions. But it was still more galling to his feelings when, in the spring of the following year (B.C. 66), he was called upon to resign the command to Pompey, who had just brought to a successful termination the war against the pirates.

The Mediterranean Sea had long been swarming with pirates. From the earliest times piracy has more or less prevailed in this sea, which, lying between three continents, and abounding with numerous creeks and islands, presents at the same time both the greatest temptations and the greatest facilities for piratical pursuits. Moreover, in consequence of the Social and Civil wars, and the absence of any fleet to preserve order upon the sea, piracy had reached an alarming height. The pirates possessed fleets in all parts of the Mediterranean, were in the habit of plundering the most wealthy cities on the coasts, and had at length carried their audacity so far as to make descents upon the Appian Road, and carry off Roman magistrates, with their lictors. All communication between Rome and the provinces was cut off, or at least rendered extremely dangerous; the fleets of corn-vessels, upon which Rome to a great extent depended for its subsistence, could not reach the city, and the price of provisions in consequence rose enormously. Such a state of things had become intolerable, and all eyes were now directed to Pompey. At the beginning of B.C. 67 the Tribune A. Gabinius brought forward a bill which was intended to give Pompey almost absolute authority over the greater part of the Roman world. It proposed that the people should elect a man with consular rank, who should possess unlimited power for three years over the whole of the Mediterranean, a fleet of 200 ships, with as many soldiers and sailors as he thought necessary, and 6000 Attic talents. The bill did not name Pompey, but it was clear who was meant. The aristocracy were in the utmost alarm, and in the Senate Cæsar was almost the only person who came forward in its support. Party spirit ran to such a height that the most serious riots ensued. Even Pompey himself was threatened by the Consul, "If you emulate Romulus, you will not escape the end of Romulus." Q. Catulus and Q. Hortensius spoke against the bill with great eloquence, but with no effect. On the day that the bill was passed the price of provisions at Rome immediately fell, a fact which showed the immense confidence which all parties placed in the military abilities of Pompey.

Pompey's plans were formed with great skill, and were crowned with complete success. He stationed his lieutenants with different squadrons in various parts of the Mediterranean to prevent the pirates from uniting, and to hunt them out of the various bays and creeks in which they concealed themselves; while, at the same time, he swept the middle of the sea with the main body of his fleet, and chased them eastward. In forty days he drove the pirates out of the western seas, and restored communication between Spain, Africa, and Italy. After then remaining a short time in Italy, he sailed from Brundusium, cleared the seas as he went along, and forced the pirates to the Cilician coast. Here the decisive action was fought; the pirates were defeated, and more than 20,000 prisoners fell into his hands. Those on whom most reliance could be placed were distributed among the small and depopulated cities of Cilicia, and a large number were settled at Soli, which was henceforward called Pompeiopolis. The second part of this campaign occupied only forty-nine days, and the whole war was brought to a conclusion in the course of three months. Pompey remained in Cilicia during the remainder of this year and the beginning of the one following. Meantime the Tribune C. Manilius brought forward a bill (B.C. 66) giving to Pompey the command of the war against Mithridates, with unlimited power over the army and the fleet in the East, and with the rights of a Proconsul in the whole of Asia as far as Armenia. As his Proconsular power already extended over all the coasts and islands of the Mediterranean in virtue of the Gabinian law, this new measure virtually placed almost the whole of the Roman dominions in his hands. But there was no power, however excessive, which the people were not ready to intrust to their favorite hero; and the bill was accordingly passed, notwithstanding the opposition of Hortensius, Catulus, and the aristocratical party. Cicero advocated the measure in an oration which has come down to us (Pro Lege Manilia), and Cæsar likewise supported it with his growing popularity and influence.

On receiving intelligence of this new appointment, Pompey immediately crossed the Taurus, and took the command of the army from Lucullus.

The power of Mithridates had been broken by the previous victories of Lucullus, and the successes which the king had gained lately were only of a temporary nature, mainly owing to the disorganization of the Roman army. In the plan of the campaign Pompey displayed great military skill. One of his first measures was to secure the alliance of the Parthian king, which not only deprived Mithridates of all hopes of succor from that quarter, but likewise cut him off from all assistance from the Armenian king Tigranes, who was now obliged to look to the safety of his own dominions. Pompey next stationed his fleet in different squadrons along the coasts of Asia Minor, in order to deprive Mithridates of all communication from the sea, and he then proceeded in person at the head of his land-forces against the king. Thus thrown back upon his own resources, Mithridates sued for peace, but, as Pompey would hear of nothing but unqualified submission, the negotiation was broken off. The king was still at the head of 30,000 foot and 2000 horse; but he knew too well the strength of a Roman army to venture an engagement with these forces, and accordingly withdrew gradually to the frontiers of Armenia. For a long time he succeeded in avoiding a battle, but he was at length surprised by Pompey in Lesser Armenia, as he was marching through a narrow pass. The battle was soon decided; the king lost the greater number of his troops, and escaped with only a few horsemen to the fortress of Synorium, on the borders of the Greater Armenia. Here he again collected a considerable force; but as Tigranes refused to admit him into his dominions, because he suspected him of fomenting the intrigues of his son against him, Mithridates had no alternative but to take refuge in his own distant dominions in the Cimmerian Bosporus. To reach them he had to march through Colchis, and to fight his way through the wild and barbarous tribes that occupied the country between the Caucasus and the Euxine. He succeeded, however, in this arduous enterprise, and reached the Bosporus in safety in the course of next year. Pompey abandoned at present all thoughts of following the fugitive king, and resolved at once to attack Tigranes, who was now the more formidable of the two monarchs.

On entering Armenia Pompey met with no opposition. He was joined by the young Tigranes, who had revolted against his father, and all the cities submitted to them on their approach. When the Romans drew near to Artaxata, the king, deserted by his army and his court, went out to meet Pompey, and threw himself before him as a suppliant. Pompey received him with kindness, acknowledged him as King of Armenia, and demanded only the payment of 6000 talents. His foreign possessions, however, in Syria, Phœnicia, Cilicia, Galatia, and Cappadocia, which had been conquered by Lucullus, were to belong to the Romans. To his son Tigranes, Sophene and Gordyene were given as an independent kingdom; but as the young prince was discontented with this arrangement, and even ventured to utter threats, Pompey had him arrested, and kept him in chains to grace his triumph.

After thus settling the affairs of Armenia, Pompey proceeded northward in pursuit of Mithridates. But the season was so far advanced that he took up his winter quarters on the banks of the River Cyrus. Early in the spring (B.C. 65) he resumed his march northward, and advanced as far as the River Phasis, but, obtaining here more certain information of the movements of Mithridates, and of the wild and inaccessible nature of the country through which he would have to march in order to reach the king, he retraced his steps, and led his troops into winter quarters at Amisus, on the Euxine. He now reduced Pontus to the form of a Roman province.

In B.C. 64 Pompey marched into Syria, where he deposed Antiochus Asiaticus, and made the country a Roman province. He likewise compelled the neighboring princes, who had established independent kingdoms on the ruins of the Syrian empire, to submit to the Roman dominion. The whole of this year was occupied with the settlement of Syria and the adjacent countries.

Next year (B.C. 63) Pompey advanced farther south, in order to establish the Roman supremacy in Phœnicia, Cœle-Syria, and Palestine. The latter country was at this time distracted by a civil war between Hyrcanus and Aristobulus. Pompey espoused the side of Hyrcanus, and Aristobulus surrendered himself to Pompey when the latter had advanced near to Jerusalem. But the Jews refused to follow the example of their king, and it was not till after a siege of three months that the city was taken. Pompey entered the Holy of Holies, the first time that any human being, except the high-priest, had penetrated into this sacred spot. He reinstated Hyrcanus in the high-priesthood, but compelled him to pay an annual tribute to Rome; Aristobulus accompanied him as a prisoner. It was during this war in Palestine that Pompey received intelligence of the death of Mithridates.

During the last two years Mithridates had been making the most extensive preparations for a renewal of the contest. He had conceived the daring project of marching round the north and west coasts of the Euxine, and penetrating even into Italy. With these views, he was busily engaged in assembling such a fleet and array as would be sufficient for an enterprise of this magnitude; but his proceedings were delayed by a long and painful illness, which incapacitated him for any personal exertion. At length, however, his preparations were completed, and he found himself at the head of an army of 36,000 men and a considerable fleet. But during his illness disaffection had made rapid progress among his followers. The full extent of his schemes was probably communicated to few; but enough had transpired to alarm the multitude, and a formidable conspiracy was organized by Pharnaces, the favorite son of Mithridates. He was quickly joined both by the whole army and the citizens of Panticapæum, who unanimously proclaimed him king, and Mithridates saw that no choice remained to him but death or captivity. Hereupon he took poison, which he constantly carried with him; but his constitution had been so long inured to antidotes that it did not produce the desired effect, and he was compelled to call in the assistance of one of his Gaulish mercenaries to dispatch him with his sword.