Rise to Power[change | change source]
After Antiochus II died his second wife Berenice declared her son Antiochus king at Antioch while his first wife Laodice declared her son Seleucus king in Ephesus. Since Antiochus was too young to be able to rule, Seleucus and Laodice had Berenice killed so that Seleucus no longer had any challenger for his throne. Ptolemy III Euergetes was angry about this so he invaded Syria and started a war.
Third Syrian War[change | change source]
Seleucus appointed his brother Antiochus Hierax as viceroy of the Seleucid Empire so that he could have Antiochus Hierax rule Syria for him while he left to fight Ptolemy. Ptolemy won most of the battles but Seleucus won enough of them that in 241 B.C.E. they agreed to a treaty which said that Ptolemy ruled all the lands he conquered but that Seleucus would stay ruler of the Seleucid Empire.
Antiochus Hierax[change | change source]
While Seleucus was off fighting the war, his brother Antiochus Hierax tried to become the new king in Asia Minor. So Seleucus started a war with Hierax to take it back. The war went on for two years and ended in a stalemate.