When she moved upon her marriage, he provided her with bottled water from the Nile, so she would never have to drink from any other source, in a particular display of personal concern.
In a public confrontation with Antioch's chief magistrate, possibly about her son having been replaced with a look-alike, Laodice struck and killed Antiochus III.
Berenice then pleaded with the assembled crowd for her son's life (not aware of his fate), gaining her sympathy from throughout the Seleucid cities.
Ptolemy III raised an army and rushed to Antioch in an attempt to save his sister, but arrived too late.
Ptolemy III set about to avenge his sister's murder by invading Syria and having Laodice killed.