(Ἀντίοχος), king of SYRIA, surnamed the GREAT (Μέγας), was the son of Seleucus Callinicus, and succeeded to the throne on the death of his brother Seleucus Ceraunus, B. C. 223, when he was only in his fifteenth year. His first cousin Achaeus, who might easily have assumed the royal power, was of great use to Antiochus at the commencement of his reign, and recovered for the Syrian monarchy all the provinces in Asia Minor, which Attalus, king of Pergamus, had appropriated to himself. But Antiochus was not so fortunate in his eastern dominions. Molo and Alexander, two brothers, who had been appointed to the government of Media and Persis respectively, revolted and defeated the armies sent against them. They were, however, put down in a second campaign, conducted by Antiochus in person, who also added to his dominions the province of Media Atropatene. (B. C. 220.)

On his return from his eastern provinces, Antiochus commenced war against Ptolemy Philopator, king of Egypt, in order to obtain Coele-Syria, Phoenicia, and Palestine, which he maintained belonged to the Syrian kingdom. At first he was completely successful. In B. C. 218, he gained possession of the chief towns of Phoenicia, but in the following year (B. C. 217), he was defeated in a great battle fought at Raphia near Gaza, and concluded in consequence a peace with Ptolemy, by which he ceded the provinces in dispute. He was the more anxious to make peace with Ptolemy, as he wished to direct all his forces against Achaeus, who had revolted in Asia Minor. In one campaign he deprived Achaeus of his conquests, and put him to death when he fell into his hands in B. C. 214, after sustaining a siege of two years in Sardis. [ACHAEUS, p. 18a.]

Antiochus seems now to have formed the design of regaining the eastern provinces of Asia, which had revolted during the reign of Antiochus II. He accordingly marched against Arsaces III., king of Parthia, and Euthydemus, king of Bactria, and carried on the war for some years. Although Antiochus met upon the whole with great success, he found it hopeless to effect the subjugation of these kingdoms, and accordingly concluded a peace with them, in which he recognized their independence. With the assistance of Euthydemus he marched into India, and renewed the alliance of the Syrian kings with that country; and he obtained from Sophagasenus, the chief of the Indian kings, a large supply of elephants. He at length returned to Syria after an absence of seven years (B. C. 212-205), which may be regarded as the most flourishing period of his reign. It appears that the title of Great was conferred upon him during this time.

In the year that Antiochus returned to Syria (B. C. 205), Ptolemy Philopator died, leaving as his successor Ptolemy Epiphanes, then a child of five years old. Availing himself of the weakness of the Egyptian government, Antiochus entered into an agreement with Philip, king of Macedonia, to divide between them the dominions of Ptolemy. As Philip became engaged soon afterwards in a war with the Romans, he was unable to send forces against Egypt; but Antiochus prosecuted this war vigorously in Palestine and Coele-Syria, and at length obtained complete possession of these provinces by his victory over the Egyptian general Scopas, near Paneas, in B. C. 198. He was assisted in this war by the Jews, to whom he granted many important privileges. Fearing, however, the power of the Romans, and anxious to obtain possession of many parts of Asia Minor which did not acknowledge his sovereignty, he concluded peace with Egypt, and betrothed his daughter Cleopatra to the young king Ptolemy, giving with her Coele-Syria and Palestine as a dowry. He now marched into Asia Minor, where he carried everything before him, and then crossed over into Europe, and took possession of the Thracian Chersonese (B. C. 196), which belonged to the Macedonian kingdom, but which he claimed as his own, because Seleucus Nicator had taken it from Lysimachus. But here his progress was stopt by the Romans. At the commencement of his war with Egypt, the guardians of young Ptolemy had placed him under the protection of the Romans ; but while the latter were engaged in their war with Philip, they did not attempt to interrupt Antiochus in his conquests, lest he should march to the assistance of the Macedonian king. Now, however, matters were changed. The Romans had conquered Philip in B. C. 197, and no longer dreaded a war with Antiochus. They accordingly sent an embassy to him (B. C. 196) requiring him to surrender the Thracian Chersonese to the Macedonian king, and also all the places he had conquered from Ptolemy. Antiochus returned a haughty answer to these demands; and the arrival of Hannibal at his court in the following year (B. C. 195) strengthened him in his determination to resist the Roman claims. Hannibal urged him to invade Italy without loss of time; but Antiochus resolved to see first what could be done by negotiation, and thus lost a most favourable moment, as the Romans were then engaged in a war with the Gauls. It was also most unfortunate for him, that when the war actually broke out, he did not give Hannibal any share in the command.

It was not till B. C. 192 that Antiochus, at the earnest request of the Aetolians, at length crossed over into Greece. In the following year (B. C. 191) he was entirely defeated by the Roman consul Acilius Glabrio at Thermopylae, and compelled to return to Asia. The defeat of his fleet in two sea-fights led him to sue for peace; but the conditions upon which the Romans offered it seemed so hard to him, that he resolved to try the fortune of another campaign. He accordingly advanced to meet Scipio, who had crossed over into Asia, but he was defeated at the foot of Mount Sipylus, near Magnesia. (B. C. 190.) He again sued for peace, which was eventually granted in B. C. 188 on condition of his ceding all his dominions west of Mount Taurus, paying 15,000 Euboic talents within twelve years, giving up his elephants and ships of war, and surrendering the Roman enemies who had taken refuge at his court. He had, moreover, to give twenty hostages for the due fulfilment of the treaty, and among them his son Antiochus (Epiphanes). To these terms he acceded, but allowed Hannibal to escape.

About this time Antiochus lost Armenia, which became an independent kingdom. He found great difficulty in raising money to pay the Romans, and was thus led to plunder a wealthy temple in Elymais ; the people, however, rose against him and killed him in his attempt. (B. C. 187.) The defeat of Antiochus by the Romans, and his death in a " fort of his own land," are foretold in the book of Daniel. (11.18, 19.) Antiochus was killed in the 52nd year of his age and the 37th of his reign. He married Laodice, daughter of Mithridates, king of Pontus, and had several children. His sons were, 1. Antiochus, who died in his father's lifetime. (Liv. 35.15.) 2. Ardys, 3. Mithridates, both of whom also probably died before their father. (Liv. 33.10.) 4. Seleucus Philopator, who succeeded his father. 5. Antiochus Epiphanes, who succeeded his brother Seleucus. The daughters of Antiochus were, 1. Laodice, married to her eldest brother Antiochus. (Appian, App. Syr. 4.) 2. Cleopatra, betrothed to Ptolemy Epiphanes. 3. Antiochis, married to Ariarathes, king of Cappadocia. 4. One whose name is not mentioned, whom her father offered in marriage to Eumenes. (Appian, App. Syr. 5.) The coins of Antiochus are the first of those of the Seleucidae which bear a date. There are two coins preserved of the 112th and 117th years of the reign of the Seleucidae, that is, the 23rd and 28th years of the reign of Antiochus. (Polyb. lib. v., &c.; Appian, Syr.; Liv. lib. xxxi.--xxxvii.; Justin. lib. xxix.--xxxii;