2. A friend of Demetrius, the son of Seleucus, who accompanied Demetrius when he went to Rome as a hostage, B. C. 175, and supported him with his advice. Apollonius had been educated together with Demetrius, and their two families had been long connected by friendship. The father of Apollonius, who bore the same name, had possessed great influence with Seleucus. (Plb. 31.19, 21.)