She was one of the daughters and youngest child born to the Seleucid Monarchs Antiochus II Theos and Laodice I.
[2][3] Laodice married Mithridates II, as a part of a political alliance between the Seleucid Empire and the Kingdom of Pontus.
[4] Through his political alliance and marriage to Laodice, Mithridates II allied himself to the most important royal house in Asia, gaining impressive recognition for Pontus as a political power in the Hellenistic world.
[3] The marriage occurred early in the reign of Seleucus II Callinicus, so he could secure Anatolia behind him, so that Seleucus II could turn his attention to war with the Egyptian Greek Pharaoh Ptolemy III Euergetes.
[4] At some point, Laodice may have influenced Mithridates II by her desire to weaken the Seleucid state, by supporting her first brother Seleucus II Callinicus in joint rule with her other brother Antiochus Hierax, who were at civil war with each other.