The throne fell to his son, Antiochus Eupator, a boy of nine, according to Appian, or, according to another authority, of twelve years of age.

The regent, Lysias, exercised the chief power, and was soon engaged in a war with the Jews, whom the death of Epiphanes had encouraged to fresh efforts.

The authority of Lysias was further disputed by a certain Philip, whom Epiphanes, shortly before his death, had made tutor to the young king.

The claims of this tutor to the regent's office being supported by a considerable portion of the army, a civil war arose between him and Lysias, which raged for the greater part of two years (B.C.

163-2), terminating in the defeat and death of Philip.