MITHRADATES III. murdered his father Phraates III. about 57 B.C., with the assistance of his brother Orodes. He was made king of Media, and waged war against his brother, but was soon deposed on account of his cruelty. He took refuge with Gabinius, the Roman proconsul of Syria. He advanced into Mesopotamia, but was beaten at Seleucia by Surenas, fled into Babylon, and after a long siege was taken prisoner and killed in 54 by .Orodes I. (Dio Cass. 39, 56; Justin 42, 4; Jos. Bell. i. 8, 7, Ant. 14, 6, 4).
A Parthian king Mithradates, who must have occupied the throne for a short time during the reign of Phraates IV., is mentioned by Jos. Ant. xvi. 8, 4, in 10 B.C.; another pretender Meherdates was brought from Rome in A.D. 49 by the opponents of Gotarzes, but defeated (Tac. Ann. xi. 10, xii. 10 sqq.). The name of another pretender Mithradates (often called Mithradates IV.) occurs on a coin of the first half of the 2nd century, written in Aramaic, accompanied by the Arsacid titles in Greek (Wroth, Catal. of the Coins of Parthia, p. 2 19) ; he appears to be identical with Meherdotes, one of the rival kings of Parthia who fought against Trajan in 116; he died in an attack on Commagene and appointed his son Sanatruces successor, who fell in a battle against the Romans (Arrian ap. Malalas, Chron. pp. 270. 274). (ED. M.)
The kings of Pontus were descended from one of the seven Persian conspirators who put the false Smerdis to death (see DARIUS I.). According to Diodorus Siculus, three members of his family Mithradates, Ariobarzanes, Mithradates were successively rulers of Cius on the Propontis and Carine in Mysia. The last of these was put to death in 302 B.C. by Antigonus, who suspected him of having joined the coalition against him. He was succeeded by his son Mithradates I. or III. (if the two dynasts of Cius be included 1 ) the founder (KTIOTTJS) of the Pontic kingdom, although this distinction is by some attributed to the father. Warned by his friend Demetrius, the son of Antigonus, that he was threatened with the same fate as his father, he fled to Paphlagonia, where he seized Cimiata, a fort at the foot of the Olgassys range. Being joined by the Macedonian garrison and the neighbouring populations, he conquered the Cappadocian and Paphlagonian territories on both sides of the Halys and assumed the title of king. Before his death he further enlarged Pontic Cappadocia. He was succeeded by Ariobarzanes, who left the throne to MITHRADATES II. (c. 256-190, according to Meyer, Mithradates II. and III.), a mere child. Early in his reign the Gauls of Galatia invaded his territory. Mithradates was at the battle of Ancyra (c. 241), in which he assisted Antiochus Hierax against his brother Seleucus Callinicus, in spite of the fact that he had married the daughter of the latter with Greater Phrygia as her dowry. His two daughters, both named Laodice, were married, one to Antiochus the Great, the other to his cousin Achaeus, a dynast of Asia Minor. He unsuccessfully attacked Sinope, which was taken by his successor Pharnaces, the brother (not the son) of MITHRADATES III. (169-121), surnamed Philopalor, Philadelphia, and Euergetes. According to Meyer, however, there were two kings (Mithradates IV. Philopator and V. Euergetes). He was the first king of Pontus to recognize the suzerainty of the Romans, of whom he was a loyal ally. He assisted Attalus II. of Pergamum to resist Prusias II. of Bithynia; furnished a contingent during the Third Punic War; and aided the Romans in obtaining possession of Pergamum, bequeathed to them by Attalus III., but claimed by Aristonicus, a natural son of 'There is much difference of opinion in regard to the kings of Pontus called Mithradates to the accession of Mithradates Eupator. Ed. Meyer reckons five, T. Reinach three.
Eumenes II. Both Mithradates and Nicomedes of Bithynia demanded Greater Phrygia in return for their services. It was awarded to Mithradates, but the senate refused to ratify the bargain on the ground of bribery. For several years the kings of Pontus and Bithynia bid against each other, till in 116 Phrygia was declared independent, although in reality it was treated as part of the province of Asia. Mithradates appears to have taken it without waiting for the decision of the senate. He invaded Cappadocia, and married his daughter to the young king, Ariarathes Epiphanes; bought the succession from the last king of Paphlagonia, and obtained a kind of protectorate over Galatia. He was a great admirer of the Greeks, who called him Euergetes; he removed his capital from Amasia to Sinope, and bestowed liberal gifts upon the temples of Delos and Athens. At the height of his power he was assassinated by his courtiers during a banquet in his palace at Sinope.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)