(Latin; " Gloriously Victorious ")
born с 265
died 225 BC
Fourth king (r. 246–225) of the Seleucid dynasty .
He became ruler when his mother poisoned his father, Antiochus II, and proclaimed him king. Her supporters made away with his Egyptian stepmother, Bernice, daughter of Ptolemy II , whom Antiochus had briefly married. Ptolemy III, Bernice's brother, responded by invading Seleucus's kingdom and taking the eastern provinces. Seleucus managed to regain northern Syria and part of Iran but was defeated by his brother (с 235), now supported by their mother, and ceded territory beyond the Taurus River. He died in a fall from his horse.