DEMETRIUS, king of Bactria, was the son of the Graeco Bactrian king Euthydemus, for whom he negotiated a peace with Antiochus the Great in 206 (Polyb. xi. 34). Soon afterwards he crossed the Hindu Kush and began the invasion of India (Strabo xi. 516) ; he conquered the Punjab and the valley of the Indus down to the sea and to Gujerat. The city of Sangala, a town of the Kathaeans in the Punjab (Arrian v. 22, 2 et seq.) he named after his father Euthydemia (Ptol. vii. i. 46) . That his power ex tended into Arachosia (Afghanistan) is proved by the name of a town Demetrias near Kandahar (Isidor, Charac. 1 g, cf. Strabo xi. 516). On his coins he wears an elephant's skin with trunk and teeth on his head ; on bronze coins, which have also an Indian legend in Kharoshti letters (see BACTRIA), he calls himself the unvanquished king (Baa tMws av0 6TO) Orlµrlrpiov) . One of his coins had already the square form used in India instead of the circular. Eventually he was defeated by the usurper Eucratides (q.v.), who meanwhile had risen to great power in Bactria. About his death we know nothing; his young son Euthydemus II. (known only from coins) can have ruled only a short time. (ED. M.) DEMETRIUS I. B.c.), King of Macedonia, sur named Poliorcetes ("Besieger"), son of Antigonus Cyclops and Stratonice. In 321 he married Phila, daughter of Antipater. At the age of twenty-two he was left by his father to defend Syria against Ptolemy the son of Lagus ; he was totally defeated near Gaza (3i2), but soon partially repaired his loss by a victory in the neighbourhood of Myus. After an unsuccessful expedition against Babylon, and several campaigns against Ptolemy on the coasts of Cilicia and Cyprus, Demetrius sailed with a fleet of 25o ships to Athens. He freed the city from the power of Cassander and Ptolemy, expelled the garrison which had been stationed there under Demetrius of Phalerum, and besieged and took Munychia (307). After these victories he was worshipped by the Athenians its a tutelary deity under the title of Soter ("Preserver"). In the campaign of 3o6 against Ptolemy he defeated Menelaus (the brother of Ptolemy) in Cyprus, and completely destroyed the naval power of Egypt.
Demetrius and his father then adopted the royal title, thereby (and by their coinage) claiming the whole of Alexander's empire. A joint expedition into Egypt, Demetrius in command of the fleet, was a failure. In 305 he endeavoured to punish the Rhodians for having deserted his cause; and his ingenuity in devising new instruments of siege, in his unsuccessful attempt to reduce the capital, gained him the appellation of Poliorcetes. He returned to Greece to deal with Cassander again. After a riotous winter in which he even shocked Athens, he drove the Cassandrian party out of the Peloponnese, called a conference at the Isthmus, and re-organized Philip's League of Corinth, much on the same lines, except that it rested on democracies in the constituent states. It was to meet at the Great Games (6 times in 4 years), and to in clude tribes (gOvn), i.e., peoples not organized into city-states. Eventually Seleucus, Cassander and Lysimachus united to destroy Antigonus and his son. The hostile armies met at Ipsus in Phrygia (3oi ). Antigonus was killed in the battle and Demetrius retired to Ephesus, defeated. Many enemies rose up against him; even the Athenians refused to admit him to their city. Demetrius ravaged the territory of Lysimachus, and effected a reconciliation with Seleucus who married his daughter. Demetrius gained pos session of Athens then oppressed by the tyranny of Lachares. In the same year (294) he established himself on the throne of Macedonia by the murder of Alexander, son of Cassander, but, expelled by the combined forces of Pyrrhus, Ptolemy and Ly simachus, he passed into Asia where he was forsaken by his troops and surrendered to Seleucus. His son Antigonus offered all his possessions and even his own liberty to have his father set free but without avail. Demetrius died in 283 after a confinement of three years.
See Life by Plutarch; Diod. Sic. xix., xx.; Wilamowitz-Moellendorff, Antigonos von Karystos; De Sanctis, Contributi alla storia Ateniese in Beloch's Situdi di storia antica (1893) ; Fergusson in Lehmann's Beitrage z. alt. Gesch. (Klio), vol. v. (1905) ; also authorities under