=28.= After the restoration of Seleucus to the government of Babylonia (see § 22), he extended his power over all the provinces between the Euphrates and the Indus. He even made war against an Indian kingdom upon the western headwaters of the Ganges, gaining thereby a great extension of commerce, and the addition of five hundred elephants to his army. The battle of Ipsus added to his dominions the country as far west as the Mediterranean and the center of Phrygia, making his kingdom by far the greatest that had been formed from the fragments of Alexander’s empire. This vast dominion was organized by Seleucus with great skill and energy. In each of the seventy-two provinces new cities sprang up, as monuments of his power and centers of Greek civilization. Sixteen of these were named Antioch, in honor of his father; five Laodice´a, for his mother, Laod´ice; seven for himself, Sel´euci´a; and several for his two wives, Apame´a and Stratoni´ce. To watch more effectually the movements of his rivals, Ptolemy and Lysimachus, he removed the seat of government from the Euphrates to his new capital, Antioch, on the Orontes, which continued nearly a thousand years to be one of the richest and most populous cities in the world. [Illustration: Coin of Antioch, twice the size of the original.] =29.= In 293 B. C., Seleucus divided his empire with his son Anti´ochus, giving the younger prince all the provinces east of the Euphrates. Demetrius Poliorcetes, after gaining and then losing Macedonia, sought to make for himself a new kingdom in Asia, out of the possessions of Lysimachus and Seleucus. He was defeated by the latter, and remained a prisoner the rest of his life. =30.= Lysimachus, king of Thrace, under the influence of his Egyptian wife and her brother, Ptolemy Cerau´nus, had alienated the hearts of his subjects by the murder of his son. The widow of the murdered prince fled for protection to the court of Seleucus, who undertook her cause and invaded the territories of Lysimachus. The two aged kings were now the only survivors of the companions and generals of Alexander. In the battle of Corupe´dion, B. C. 281, Lysimachus was slain, and all his Asiatic dominions were transferred to Seleucus. The empire of Alexander seemed about to be united in the hands of one man. Before crossing the Hellespont to seize the European provinces, the Syrian king committed the government of his present dominion to his son, Antiochus. Then passing the strait, he advanced to Lys´imachi´a, the capital of his late enemy; but here he was killed by the hand of Ptolemy Ceraunus, B. C. 280. Thrace and Macedonia became the prize of the murderer.