the name of several kings of Pontus, of whom the most distinguished was Mithridates VI., surnamed Eupator, and usually styled "The Great," King of Pontus, who succeeded his father, Mithridates V., at the age of eleven, about 120 B.C. His reign began amid daring conspiracies, which summoned up prematurely his great tact and intrepidity. Afraid of being poisoned by his treacherous subjects, he followed the practice of swallowing antidotes, until his frame became thoroughly fortified against the action of the most deadly drugs. The more open attempts against his life he baffled by incessant activity. There was no warlike exercise in which he did not engage, and none in which he did not excel. He was also a keen and daring hunter, pursuing his sport into distant and desolate regions, disturbing the lair of the most savage animals, and sleeping on the ground under the most inclement skies. Under such a thorough training, he acquired an iron strength, great agility, a stature almost gigantic, and a spirit indifferent to the presence of any danger. His mind meanwhile was not neglected. He studied with success the physics and philosophy of that age, and cultivated his mind with so much diligence, that he is said to have acquired the languages of no less than twenty-five of the neighbouring nations. At the age of eighteen Mithridates began to govern in his own person. One of his first public acts, it is said, was to render his claim to the throne undisputed by the assassination of his mother and brother. He then directed the entire strength of his kingdom to foreign conquest. Leading his armies eastward along the shore of the Euxine, he conquered Lesser Armenia, Colchis, and other barbarian kingdoms. The wild Scythians of the Tanais, who had dared the might of so many conquering kings, were compelled to submit to his yoke; and his generals being then entrusted with the command of his armies, extended his conquests as far as the River Tyras (Dniester), and exacted tribute from the Tauric Chersonese. Shortly afterwards he seized upon the sovereignty of Bosporus, left vacant by the death of Parisades.

With his strength and resources thus augmented, Mithridates formed the design of wresting all the Asiatic states from the powerful grasp of Rome. Cautiously making his preparations, he first travelled in disguise through Asia Minor, and employed his intimate knowledge of the different languages of that country in ascertaining from the inhabitants the state of their defences and their feelings towards their Roman masters. He then formed an alliance with the Parthians and Iberians, and married his daughter to Tigranes, the powerful King of Armenia. He even entertained the gigantic design of banding together in one great league all the foes of Rome, and of convulsing her sovereignty in all parts of the world by one general shock. His legates accordingly travelled as far as the pillars of Hercules, negotiating with the rebel Marians and every people and predatory band that were up in arms against the Romans. Before these preparations were completed he became involved in a war with his nephew Ariarathes, King of Cappadocia, who was an ally of the Romans. Ariarathes fell in battle, and Mithridates placed his own son upon the vacant throne. Rome, however, interfered, and seized the Cappadocian crown for Ariobarzanes, a creature of her own. Mithridates succumbed for a time; but about 90 B.C. he openly attacked and deposed the puppet of the Romans. At the same period he wrested the sceptre from the young King Nicomedes of Bithynia, another tributary of the Romans. Both the wronged sovereigns laid their cases before the senate of Rome, and were reinstalled in their dominions. Mithridates again submitted; but no long time had elapsed before he was lying at the head of an army of 300,000 waiting for the Romans or their allies to strike the first blow. He did not wait long. Nicomedes, at the instigation of the Romans, invaded Pontus. Mithridates then poured his troops into Cappadocia, and in a short time overran and subdued the whole country. As speedily did his generals Archaean and Neoptolemus prostrate the might of Nicomedes in a great battle on the banks of the Amnias, and wrest Bithynia from the remnants of his army. The neighbouring states, eagerly hailing the outbreak of a war that seemed likely to free them from the insatiable rapacity of their Roman oppressors, raised the standard of revolt. All the cities of Asia Minor, with a few exceptions, flung open their gates to the victorious King of Pontus, and he marched westward without opposition to the shores of the Aegean Sea. Lesbos, Delos, Euboea, and the islands of the Cyclades, were next subjected to his sway, and even Athens was betrayed into the hands of his general Archaean. In the height of his triumph Mithridates repaired to Pergamus, and abandoned himself to luxury and pleasure. It was then that he issued a decree for the extermination of all the Roman citizens in Asia Minor. With an eager promptitude the vengeful natives obeyed the order; and the massacre of 80,000, or according to some, of 150,000 Romans, cut off Mithridates from all chance of reconciliation with his powerful foes. About the middle of 87 B.C. he was roused to his former activity by the news that a Roman army under Sylla was approaching Greece. He immediately despatched Taxiles with an immense force to co-operate with Archaean. In the following year, however, the news arrived that Athens had been captured, and that his troops had been routed at the battle of Charonea. With unslackened perseverance he equipped another army of 80,000, and sent it under the command of Dorylaus to the scene of conflict. But the tide of fortune was running against him; and in 85 B.C. his position had become critical. The time-serving Asiatics, estranged by his growing misfortunes, were rising in revolt around him, and assassinating the tetrarchs he had placed over them. An army sent by the Marian party at Rome had invaded Asia Minor, had defeated a large force under his son Mithridates, and was pursuing himself from place to place. About the same time he received the intelligence of the almost utter annihilation of his Grecian troops at Orchomenus. Almost his only resource, therefore, was a treaty of peace. This, after some difficulty, he purchased from Sylla in 84 B.C., at the expense of 2000 talents, 70 ships, and all the territories he had wrested from the Romans.

In spite of this treaty, Mithridates knew well that nothing less than his complete humiliation would satisfy his haughty enemies, and therefore he resolved to prepare for the worst. Several years were spent in building navies, in collecting magazines of arms and provisions, in recruiting his army, and in gathering hordes of mercenaries from every quarter both in Asia and in Europe. He equipped his troops with Roman arms, and attempted to infuse into them the magnanimous Roman valour by subjecting them to the severe Roman discipline. He even entered into an alliance with Sertorius the great Marian general in Spain. After such preparations he was bold enough, on the death of Nicomedes III. in 74 B.C., to lay claim to the vacant throne of Bithynia. He then burst into that country with a mighty army, swept through it without encountering opposition, and overwhelmed the forces of Cotta the praetor under the walls of Chalcedon. Marching then into Mysia, he sat down before Cyzicus, and invested that city by land and sea. Thither Lucullus the Roman general followed him. For some time the two armies lay encamped near each other without meeting in any general engagement. At last Mithridates, unable to provide for so large an army in so narrow a territory, was forced to raise the siege and to commence a retreat towards the west. Lucullus then hovered about his rear, threw his army into confusion, and took many prisoners. With great difficulty Mithridates embarked his shattered forces and set sail homewards. On the way a storm sunk his fleet, and he arrived in his own dominions with a fragment of that magnificent army with which he had set out. Yet Mithridates still retained his invincible energy, and that soon supplied him with another army. By the spring of 72 B.C. he had organized a large force of his own subjects, of Scythians, and of Parthians, and awaited the arrival of Lucullus in an impregnable position among the mountains at Cabira. Lucullus arrived, but found that his enemy had learned a lesson from former misfortunes, and that he was resolved to act merely on the defensive. He attempted to dislodge him, but was repulsed with great loss. In a short time he discovered that his provisions were effectually cut off, and that want was beginning to lay waste his camp. At this crisis an accident saved him. The forces of Mithridates, compelled by a misfortune to shift their camp, were struck with a sudden panic. A headlong flight ensued, and their ranks were cut to pieces and scattered over the whole country by the pursuing Roman cavalry. The King himself, after braving many dangers in his desperate attempts to rally his troops, fled to the kingdom of his son-in-law Tigranes, and left all his dominions in the power of Lucullus.

In 69 B.C. Tigranes mustered a large army to vindicate the cause of his father-in-law, and at the same time to defend his own territories against the invading Romans; but risking, in opposition to the advice of Mithridates, a pitched battle at Tigranocerta, he was defeated by Lucullus with great slaughter. The ensuing winter was spent by Mithridates in equipping a select force of 70,000 with Roman armour, and in inuring them to Roman discipline. In the summer of 68 B.C. he commenced to harass the advance of Lucullus into Armenia by cutting off his foraging parties, and by galling his rear with bodies of skirmishers. At length he was brought to a general engagement near Artaxata, and suffered a severe defeat. But no sooner had the enemy marched into Mesopotamia to lay siege to the strong fortress of Nisibis, than Mithridates betook himself to Pontus at the head of 4000 chosen troops, and commenced a sudden and daring guerilla war. Garrison after garrison was surprised and wrested from the Romans; his old soldiers rallied round his standard; the army under Fabius, the lieutenant of Lucullus, was cut to pieces; and when winter suspended the contest, Triarius was the only Roman commander who was capable of offering any effectual resistance. With him Mithridates prepared to engage in the spring of 87 B.C. A pitched battle soon took place, in which the Romans, after an obstinate struggle, fled, leaving their camp in the hands of the enemy and 7000 of their officers and private soldiers lying dead on the field. This defeat, the most disastrous blow that had fallen upon Rome for many years, left the greater part of Pontus in the hands of Mithridates.

The King of Pontus was engrossed with the re-organization of his government when Pompey the Great arrived in Asia in 66 B.C. to supersede Lucullus. That able general immediately formed an alliance with the Parthian king, and thus rendered it necessary for Tigranes to keep his troops for the protection of his own dominions. Mithridates was accordingly left to meet his great antagonist all alone. At first he tried negotiation, but scorned to stoop to the conditions that were offered to him. He then placed himself at the head of 32,000 well-disciplined troops, and resorted to his former plan of defensive warfare. For some time he attended the movements of the Romans, intercepting their provisions, destroying their foragers, and baffling Mitrowicz all their attempts to force him to a general engagement.

At length desperation drove Pompey to attack him by night Mitweida, on the banks of the Euphrates. An accident spread a panic through the king's forces; in a few moments there was a general flight; and the greater part of the Pontine army were either slain by the Romans or drowned in attempting to cross the river. Mithridates himself, at the head of a few horsemen, cut his way through the legions of the enemy, and escaped to the border stronghold of Synoria. Thence he hastened with a considerable body of troops to take refuge in Armenia. But dread of the Romans prevented Tigranes from giving him any countenance. The only retreat now left to him was the kingdom of Bosporus, over which his son Machares reigned. Thither, therefore, he directed his course by forced marches through the country of Colchis, until he arrived at Dioscurias. Assured then that he was beyond the reach of Pompey, he halted, and passed the winter enlisting troops and equipping a fleet for the remainder of his journey. In 65 B.C. he continued his march through the midst of the most savage tribes, exciting the opposition of some and the enthusiastic admiration of others, yet pressing onwards with irresistible constancy. At length he arrived at Panticapaeum, the capital of the kingdom of Bosporus, and found that his son Machares, who had formerly sent in his submission to the Romans, had put an end to his life on hearing of his approach. Mithridates accordingly seated himself in the vacant throne. His newly-acquired power was far beyond the reach of the grasping tyranny of Rome, and he might now have rested from that disastrous struggle in which he had been engaged for the last twenty-six years. Yet hardly had he organized his government, when he conceived the daring plan of marching at the head of a large army round the north and west coasts of the Euxine, of rallying round his standard all those barbaric tribes who cherished a deadly enmity towards Rome, of bursting with an overwhelming horde into the Roman possessions, and of even penetrating into Italy and striking at the Eternal City itself. With all possible speed he set himself to muster the strength of his kingdom, and soon saw himself at the head of an army of 36,000, supported by a considerable fleet. However, as the desperate nature of the coming expedition began to be generally known, the soldiers began to falter in their allegiance. This growing disaffection speedily swelled into open revolt, through the intrigues of Pharnaces, the king's own son and heir. In vain did Mithridates attempt to awe his troops into obedience, and to excite filial regard in his son. He was forced to flee for his life into a strong fortress. There he resolved to die, that he might not fall alive into the hands of his remorseless subjects. He tried to poison himself; but his iron constitution, even at the age of sixty-eight, was proof against the deadly drug, and he was compelled to die on the sword of a faithful Gallic mercenary.

Mithridates is described by Petereclus as "a man who can neither be mentioned nor passed over without caution; most valiant in war, unrivalled for valour,—renowned at one time for success, at all times for magnanimity,—a general in council, a soldier in action, and a very Hannibal in his hatred of the Romans."