[4] Antiochus's father was Seleucus I Nicator[5][6] and his mother was Apama, daughter of Spitamenes,[7][8] being one of the princesses whom Alexander the Great had given as wives to his generals in 324 BC.

[9][10] The Seleucids fictitiously claimed that Apama was the daughter of Darius III, in order to legitimise themselves as the inheritors of both the Achaemenids and Alexander, and therefore the rightful lords of western and central Asia.

[11] In 294 BC, prior to the death of his father Seleucus I, Antiochus married his stepmother, Stratonice, daughter of Demetrius Poliorcetes.

Antiochus was soon compelled to make peace with his father's murderer, Ptolemy Keraunos, apparently abandoning Macedonia and Thrace.

Around 262 BC Antiochus tried to break the growing power of Pergamum by force of arms, but suffered defeat near Sardis and died soon afterwards.

The 3rd century Greek writer Athenaeus, in his Deipnosophistae, mentions an incident that he learned from Hegesander's writings: Bindusara requested Antiochus to send him sweet wine, dried figs and a sophist.

Antiochus replied that he would send the wine and the figs, but the Greek laws forbade him to sell a sophist.