Complex sentence: After the death of Ptolemy II, Antiochus II left his second family in Antioch and returned to Laodice I. Antiochus II named his first son with Laodice I as his successor to the throne.
Split into simpler sentences: After the death of Ptolemy II, Antiochus II left his second family in Antioch and returned to Laodice. He named his first son with Laodice as his successor to the throne.