=54.= Ptolemy II. was engaged in various wars; first for the furtherance of the Achæan League, and the protection of the Greeks against Macedonian aggressions; afterward against his half-brother, Magas, king of Cyrene, and the kings of Syria, with whom Magas was allied. He gained possession of the whole coast of Asia Minor, with many of the Cyclades. By the wisdom of his internal policy, Egypt was meanwhile raised to her highest pitch of wealth and prosperity. He re-opened the canal made by Rameses the Great (see Book I, §§ 153, 154), and built the port of Arsinoë, on the site of the modern Suez. To avoid the dangers of Red Sea navigation, he founded two cities, named Berenice, farther to the southward, and connected one of them by a highway with Coptos on the Nile. Egypt thus reaped the full commercial advantage of her position midway between the East and the West. For centuries the rich productions of India, Arabia, and Ethiopia were conveyed along these various highways to Alexandria, whence they were distributed to Syria, Greece, and Rome. The revenues of Egypt were equal to those which Darius had derived from the vast empire of Persia. =55.= The personal character of Philadelphus was less admirable than that of his father. He killed two of his brothers, banished a most faithful counselor, and by marrying his own sister, Arsinoë, introduced a custom which caused untold misery and mischief in the kingdom. He died B. C. 247, having reigned thirty-eight years, or thirty-six from the death of his father. =56.= Ptolemy III. (Euergetes) was the most enterprising monarch of his race, and pushed the boundaries of his kingdom to their greatest extent. He gained the Cyr´ena´ica by marriage with the daughter of Magas, and annexed portions of Ethiopia and Arabia. In his war against Syria to avenge his sister Berenice (see §§ 32, 33), he even passed the Euphrates and conquered all the country to the borders of Bactria; but he lost all this by his sudden recall to Egypt. His conquests on the sea-board, which could be defended by his fleet, remained permanently in his possession. All the shores of the Mediterranean, from Cyrene to the Hellespont, with many important islands, and even a portion of Europe, including Lysimachia in Thrace, belonged to his dominion.