Surnamed Eupator, king of Pontus from 123 to 63 B.C.; an implacable enemy of the Romans, between whom and him there raged from 90 to 63 a succession of wars, till he was defeated by Pompey near the Euphrates, when, being superseded by his son, he put an end to his life; he was a great man and conqueror, subdued many surrounding nations, and was a collector of works of art; he made a special study of poisons, and familiarised himself with all their antidotes, in view of possible attempts by means of them to take away his life.