Ptolemy III Euergetes (ca. 284–222 bc). Third ruler of the Ptolemaic dynasty in Egypt; son and successor of Ptolemy II Philadelphus and his first wife, Arsinoe I.

Ptolemy III began his reign by invading Syria to avenge the murder of his sister, Berenice, and her son by Antiochus II, to whom she had been given as part of the peace after the Second Syrian War (260–255 bc). Antiochus II had divorced and exiled his then-wife, Laodice, with their son, Seleucus II, to marry Berenice. When Antiochus died in 247, Laodice returned from exile to see her son, Seleucus II, take his father’s throne. When it appeared that Berenice’s son would be heir instead, Laodice had Berenice and her son assassinated to ensure Seleucus’ place.

In the Third Syrian (or Laodicean) War (246–241 bc) between the Ptolemies and the Seleucids, Ptolemy III gained Seleucid territory in Asia Minor and Thrace. However, when the disarray of the royal succession in Syria settled down and Seleucus II rallied his forces, Ptolemy’s advances were stopped. A domestic revolt then forced him to withdraw entirely from Syria and return to Egypt. He did not lose his gains from the war since Seleucus also had significant domestic issues to address and so did not press his advantage. For the next 10 years, Ptolemy III focused his attention on domestic issues. By the 220s, he had done much to restore Egypt’s prosperity.