In 204 BC King Ptolemy IV Philopator of Egypt died, leaving the throne to his six-year-old son Ptolemy V. Philip V of Macedon and Antiochus the Great of the Seleucid Empire decided to exploit the weakness of the young king by taking Ptolemaic territory for themselves and they signed a secret pact defining spheres of interest, opening the Fifth Syrian War. Philip first turned his attention to the independent Greek city states in Thrace and near the Dardanelles. His success at taking cities such as Kios worried the state of Rhodes and King Attalus I of Pergamon who also had interests in the area.