Son of Antiochus I who regained control of the provinces in Asia Minor & Phoenicia that his father had lost, by forming an alliance with Antigonus II of Macedon against Ptolemy II of Egypt.  To gain the support of Syrian Jews he granted them citizenship. The citizens of Miletus [Asia Minor] proclaimed him a god [Greek: theos] for expelling the tyrant who oppressed them (255 BCE). But the price of a peace treaty with Egypt (ca. 252 BCE) was divorce from his half-sister Laodice to marry Berenice, the daughter of Ptolemy. Though he repudiated Berenice and reinstated Laodice, the latter soon poisoned him to guarantee their son the throne.  The subsequent war between Seleucid & Ptolemaic forces cost Antiochus' heirs more than he had gained.

 References: Josephus, Antiquities 7.43, 12.125.
                   Appian, History of Rome: the Syrian Wars 65.

Other resources on line:

• Antiochus II Theos - article in Wikipedia's web.

• Antiochus II Theos - Jona Lendering's brief biographical sketch with list of links to primary sources [Livius: Articles on Ancient History].

Though subjects at Miletus divinized Antiochus II, the Seleucid king never directly identified himself as "god" (theos). Rather, like other early Seleucid kings of the same name, his coins bore the simple inscription: Basileos Antiochou ["of King Antiochus"].  The iconography on this silver tetradrachma is typical of early Seleucid coinage. The face bears the likeness of the king wearing the royal diadem.  The other side portrays Apollo seated with bow & arrow on a phallic stone.

For high resolution images of this and other coins of Antiochus II see Ancient Coinage of Seleucia, Antiochos II in David Surber's excellent ancient coins website: Wildwinds.