surnamed EUERGETES, was the son of Pharnaces I. and grandson of
the preceding. (Just. 38.5; Clinton. F. H.
vol. iii. p. 426.) The period of his accession is wholly uncertain; we only know that he was
on the throne in B. C. 154, when he is mentioned as sending an
auxiliary force to the assistance of Attalus II. against Prusias, king of Bithynia. (Plb. 33.10.) But as much as twenty-five years before (B. C. 179), his name is associated with that of his father in the treaty
concluded by Pharnaces with Eumenes, in a manner that would lead one to suppose he was already
admitted to some share in the sovereign power. (Plb. 26.6.) He was
the first of the kings of Pontus who entered into a regular alliance with the Romans, whom he
supported with some ships and a small auxiliary force during the third Punic war. (Appian,
App. Mith. 10.) At a subsequent period he rendered them more
efficient assistance in the war against Aristonicus (B. C. 131-129), and for his services on this occasion was rewarded by the consul
M'. Aquillius with the province of Phrygia. The acts of Aquillius were rescinded by the senate
on the ground of bribery, but it appears that Mithridates continued in possession of Phrygia
till his death. (Just. 37.1, 38.5;
Appian, App. Mith. 12, 56,
57 ; Oros. 5.10; Eutrop. 4.20, who, however, confounds him with his son.) The close of
his reign carl only be determined approximately, from the statements concerning the accession
of his son, which assign it to the year 120. He was assassinated at Sinope by a conspiracy
among his own immediate attendants. (Strab. x. p.477.)