The second son of Antiochus
VIII sought to avenge the death of his brother Seleucus VI at the
hands of their cousin, Antiochus
X. But less than 2 years later he was himself killed in trying to
capture Antioch. His cause was taken up by his younger brothers, Philip I &
Demetrius III, who succeeded in taking control of major portions of their
cousin's realm, effectively dividing & diluting Seleucid
power.