On the death of Artabanus II., about B.C. 124, his son, Mithridates II., was proclaimed king. Of this monarch, whose achievements (according to Justin) procured him the epithet of "the Great," the accounts which have come down to us are extremely scanty and unsatisfactory. Justin, who is our principal informant on the subject of the early Parthian history, has unfortunately confounded him with the third monarch of the name, who ascended the throne more than sixty years later, and has left us only the slightest and most meagre outline of his actions. The other classical writers, only to a very small extent, supplement Justin's narrative; and the result is that of a reign which was one of the most important in the early Parthian series, the historical inquirer at the present day can form but a most incomplete conception.
Victory in the east
It appears, however, from the account of Justin, and from such other notices as have reached us of the condition of things at this time in the regions lying east of the Caspian, that Mithridates was entirely successful where his father and his cousin had signally failed. He gained a number of victories over the Scythic hordes; and effectually checked their direct progress towards the south, throwing them thereby upon the east and the south-east. Danger to Parthia from the Scyths seems after his reign to have passed away. They found a vent for their superabundant population in Seistan, Afghanistan, and India, and ceased to have any hopes of making an impression on the Arsacid kingdom. Mithridates, it is probable, even took territory from them. The acquisition of parts of Bactria by the Parthians from the Scyths, which is attested by Strabo, belongs, in all likelihood, to his reign; and the extension of the Parthian dominion to Seistan may well date from the same period.
Justin tells us that he added many nations to the Parthian Empire. The statements made of the extent of Parthia on the side of Syria in the time of Mithridates the First render it impossible for us to discover these nations in the west: we are, therefore, compelled to regard them as consisting of races on the eastern frontier, who could at this period only be outlying tribes of the recent Scythic immigration.
War in Armenia
The victories of Mithridates in the East encouraged him to turn his arms in the opposite direction, and to make an attack on the important country of Armenia, which bordered his north-western frontier. Armenia was at the time under the government of a certain Ortoadistus, who seems to have been the predecessor, and was perhaps the father, of the great Tigranes.
Mithridates II., having given an effectual check to the progress of the Scythians in the east, determined to direct his arms towards the west, and to attack the dominions of his relative, the third of the Armenian Arsacidse. Of the circumstances of this war, and its results, we have scarcely any knowledge. Justin, who alone distinctly mentions it, gives us no details. A notice, however, in Strabo, which must refer to about this time, is thought to indicate with sufficient clearness the result of the struggle, which seems to have been unfavorable to the Armenians. Strabo says that Tigranes, before his accession to the throne, was for a time a hostage among the Parthians. As hostages are only given by the vanquished party, we may assume that Ortoadistus (Ardashes) found himself unable to offer an effectual resistance to the Parthian king, and consented after a while to a disadvantageous peace, for his observance of which hostages were required by the victor.
Contact with Rome
It cannot have been more than a few years after the termination of this war, which must have taken place towards the close of the second, or soon after the beginning of the first century, that Parthia was for the first time brought into contact with Rome.
The Great Republic, which after her complete victory over Antiochus III., B.C. 190, had declined to take possession of a single foot of ground in Asia, regarding the general state of affairs as not then ripe for an advance of Terminus in that quarter, had now for some time seen reason to alter its policy, and to aim at adding to its European an extensive Asiatic dominion. Macedonia and Greece having been absorbed, and Carthage destroyed (B.C. 148-146), the conditions of the political problem seemed to be so far changed as to render a further advance towards the east a safe measure; and accordingly, when it was seen that the line of the kings of Pergamus was coming to an end, the Senate set on foot intrigues which had for their object the devolution upon Rome of the sovereignty belonging to those monarchs.
By clever management the third Attalus was induced, in repayment of his father's obligations to the Romans, to bequeath his entire dominions as a legacy to the Republic. In vain did his illegitimate half-brother, Aristonicus, dispute the validity of so extraordinary a testament; the Romans, aided by Mithridates IV., then monarch of Pontus, easily triumphed over such resistance as this unfortunate prince could offer, and having ceded to their ally the portion of Phrygia which had belonged to the Pergamene kingdom, entered on the possession of the remainder. Having thus become an Asiatic power, the Great Republic was of necessity mixed up henceforth with the various movements and struggles which agitated Western Asia, and was naturally led to strengthen its position among the Asiatic kingdoms by such alliances as seemed at each conjuncture best fitted for its interests.
Hitherto no occasion had arisen for any direct dealings between Rome and Parthia. Their respective territories were still separated by considerable tracts, which were in the occupation of the Syrians, the Cappadocians, and the Armenians. Their interests had neither clashed, nor as yet sufficiently united them to give rise to any diplomatic intercourse. But the progress of the two Empires in opposite directions was continually bringing them nearer to each other; and events had now reached a point at which the Empires began to have (or seem to have) such a community of interests as led naturally to an exchange of communications.
A great power had been recently developed in these parts. In the rapid way so common in the East. Mithridates VI., of Pontus, the son and successor of Rome's ally, had, between B.C. 112 and B.C. 93, built up an Empire of vast extent, numerous population, and almost inexhaustible resources from the insignificant kingdom of Pontus on the Black Sea . He had established his authority over Armenia Minor, Colchis, the entire east coast of the Black Sea, the Chersonesus Taurica, or kingdom of the Bosporus, and even over the whole tract lying west of the Chersonese as far as the mouth of the Tyras, or Dniester. Nor had these gains contented him. He had obtained half of Paphlagonia by an iniquitous compact with Nicomedes, King of Bithynia; he had occupied Galatia; and he was engaged in attempts to bring Cappadocia under his influence. In this last-named project he was assisted by the Armenians, with whose king, Tigranes, he had (about B.C. 96) formed a close alliance, at the same time giving him his daughter, Cleopatra, in marriage. Rome, though she had not yet determined on war with Mithridates, was resolved to thwart his Cappadocian projects, and in B.C. 92 sent Sulla into Asia with orders to put down the puppet whom Mithridates and Tigranes were establishing, and to replace upon the Cappadocian throne a certain Ariobarzanes, whom they had driven from his kingdom. In the execution of this commission, Sulla was brought into hostile collision with the Armenians, whom he defeated with great slaughter, and drove from Cappadocia together with their puppet king. Thus, not only did the growing power of Mithridates of Pontus, by inspiring Rome and Parthia with a common fear, tend to draw them together, but the course of events had actually given them a common enemy in Tigranes of Armenia, who was equally obnoxious to both.
For Tigranes, who, during the time that he was a hostage in Parthia, had contracted engagements towards the Parthian monarch which involved a cession of territory, and who in consequence of his promises had been aided by the Parthians in seating himself on his father's throne though he made the cession required of him in the first instance had soon afterwards repented of his good faith, had gone to war with his benefactors, recovered the ceded territory, and laid waste a considerable tract of country lying within the admitted limits of the Parthian kingdom. These proceedings had, of course, alienated Mithridates and we may with much probability ascribe to them the step, which he now took, of sending an ambassador to Sulla. Orobazus, the individual selected, was charged to propose an alliance offensive and defensive between the two countries. Sulla received the overture favorably, but probably considered that it transcended his powers to conclude a treaty; and thus nothing more was effected by the embassy than the establishment of a good understanding between the two States.
Contact between Parthia and China
Until about 140 B.C. China had no real knowledge of the West. In the Han dynastymissions were sent to many countries including Parthia, which was termed Anxi 安息 under Zhang Qian who visited Bactria and Parthia in 126 B.C. Zhang Qian reported rice, wheat and the vine was cultivated with great walled cities and siver coinage .
Soon after this Tigranes appears to have renewed his attacks upon Parthia, which in the interval between B.C. 92 and B.C. 83 he greatly humbled, depriving it of the whole of Upper Mesopotamia, at this time called Gordyene, and under rule of one of the Parthian tributary kings. Of the details of this war we have no account; and it is even uncertain whether it fell within the reign of Mithridates II. or no. The unfortunate mistake of Justin, whereby he confounded this monarch with Mithridates III., has thrown this portion of the Parthian history into confusion, and has made even the successor of Mithridates II. uncertain.
Mithridates II. probably died about B.C. 89, after a reign which must have exceeded thirty-five years.
Legacy of Mithridates
His great successes against the Scythians in the earlier portion of his reign were to some extent counterbalanced by his losses to Tigranes in his old age; but on the whole he must be regarded as one of the more vigorous and successful of the Parthian monarchs, and as combining courage with prudence. It is to his credit that he saw the advantage of establishing friendly relations with Rome at a time when an ordinary Oriental monarch might have despised the distant Republic, and have thought it beneath his dignity to make overtures to so strange and anomalous a power. Whether he definitely foresaw the part which Rome was about to play in the East, we may doubt; but at any rate he must have had a prevision that the part would not be trifling or insignificant. Of the private character of Mithridates we have no sufficient materials to judge. If it be true that he put his envoy, Orobazus, to death on account of his having allowed Sulla to assume a position at their conference derogatory to the dignity of the Parthian State, we must pronounce him a harsh master; but the tale, which rests wholly on the weak authority of the gossip-loving Plutarch, is perhaps scarcely to be accepted.