Background and early reign Antiochus III was a member of the
Hellenistic Seleucid dynasty. He was the son of king
Seleucus II Callinicus and
Laodice II, aunt of Seleucus, and was born around 242 BC near
Susa in
Persia. He may have initially borne a non-dynastic name (starting with Ly-), according to a Babylonian chronicle. He succeeded, under the name Antiochus, his brother
Seleucus III Ceraunus, upon the latter's murder in Anatolia; he was in Babylon at the time. Antiochus III inherited a disorganized state. Not only had
Asia Minor become detached, but the easternmost provinces had broken away,
Bactria under the Seleucid
Diodotus of Bactria, and
Parthia under the rebel satrap
Andragoras in 247–245 BC, who was himself later vanquished by the nomad chieftain
Arsaces. In 222 BC, soon after Antiochus's accession,
Media and
Persis revolted under their governors, the brothers
Molon and
Alexander. The young king, under the influence of the minister
Hermeias, headed an attack on Ptolemaic Syria instead of going in person to face the rebels. The attack against the Ptolemaic empire proved a fiasco, and the generals sent against Molon and Alexander met with disaster. Only in Asia Minor, where the king's cousin,
Achaeus, represented the Seleucid cause, did its prestige recover, driving the Pergamene power back to its earlier limits. In 221 BC Antiochus at last went far east, and the rebellion of Molon and Alexander collapsed which
Polybius attributes in part to his following the advice of
Zeuxis rather than Hermeias. The submission of Lesser Media, which had asserted its independence under
Artabazanes, followed. Antiochus conspired with his physician and allies to have Hermeias assassinated, and then returned to
Syria (220 BC). Meanwhile, Achaeus himself had revolted and assumed the title of king in Asia Minor. Though, due to the brewing mutiny of his troops arising from their dissatisfaction over his rebellion against their king, Achaeus desisted from his attempted coup and retreated. While sending additional threats to Achaeus, Antiochus left him for the time being and renewed his attempts on Ptolemaic Syria. Euthydemus was defeated by Antiochus at the
Battle of the Arius, but after resisting the Seleucid king in the
Siege of Bactra, he obtained an honourable peace by which Antiochus promised Euthydemus's son
Demetrius the hand of Laodice, his daughter, and allowed Euthydemus himself to keep his royal title. Antiochus next, following in the steps of Alexander, crossed into the
Kabul valley, reaching the realm of Indian king
Sophagasenus and returned west by way of
Seistan and
Kerman (206/5). In 205/204 BC the infant
Ptolemy V Epiphanes succeeded to the Egyptian throne, and Antiochus is said (notably by
Polybius) to have concluded a secret pact with
Philip V of Macedon for the partition of the Ptolemaic possessions. In 192 BC Antiochus invaded Greece with a 10,000-man army, and was elected the commander in chief of the
Aetolian League. In 191 BC, however, the Romans under
Manius Acilius Glabrio routed him at
Thermopylae, forcing him to withdraw to Asia Minor. The Romans followed up their success by invading
Anatolia, and the decisive victory of
Scipio Asiaticus at
Magnesia ad Sipylum (190 BC), following the defeat of Hannibal at sea off
Side, delivered Asia Minor into their hands. By the
Treaty of Apamea (188 BC) Antiochus abandoned all the country north and west of the
Taurus Mountains, most of which the Roman Republic gave either to Rhodes or to the Attalid ruler
Eumenes II, its allies (many Greek cities were left free). As a consequence of this blow to the Seleucid power, the outlying provinces of the empire, recovered by Antiochus, reasserted their independence. Antiochus mounted a fresh eastern expedition in
Luristan, where he was killed while pillaging a temple of
Bel at
Elymaïs, Persia, in 187 BC. ==Family==