Ptolemy, on reaching Alexandria, set his army in motion towards Pelusium, on its way to Palestine.  His forces were eighteen thousand foot and four thousand horse, part Macedonians, as the Greeks living in Egypt were always called, and part mercenaries, followed by a crowd of Egyptians, of whom some were armed for battle, and some were to take care of the baggage.  He had twenty-two thousand Greeks, and was met at Gaza by the young Demetrius with an army of eleven thousand foot and twenty-three hundred horse, followed by forty-three elephants and a body of light-armed barbarians, who, like the Egyptians in the army of Ptolemy, were not counted.  But the youthful courage of Demetrius was no match for the cool skill and larger army of Ptolemy; the elephants were easily stopped by iron hurdles, and the Egyptian army, after gaining a complete victory, entered Gaza, while Demetrius fled to Azotus.  Ptolemy, in his victory, showed a generosity unknown in modern warfare; he not only gave leave to the conquered army to bury their dead, but sent back the whole of the royal baggage which had fallen into his hands, and also those personal friends of Demetrius who were found among the prisoners; that is to say, all those who wished to depart, as the larger part of these Greek armies were equally ready to fight on either side.

By this victory the whole of Phoenicia was again joined to Egypt, and Seleucus regained Babylonia.  There, by following the example of Ptolemy in his good treatment of the people, and in leaving them their own laws and religion, he founded a monarchy, and gave his name to a race of kings which rivalled even the Lagidae.  He raised up again for a short time the throne of Nebuchadnezzar.  But it was only for a short time.  The Chal-dees and Assyrians now yielded the first rank to the Greeks who had settled among them; and the Greeks were more numerous in the Syrian portion of his empire.  Accordingly Seleucus built a new capital on the river Orontes, and named it Antioch after his father.  Babylon then yielded the same obedience to this new Greek city that Memphis paid to Alexandria.  Assyria and Babylonia became subject provinces; and the successors of Seleucus, who came to be known as Selucids, styled themselves not kings of Babylon but of Syria.

When Antigonus, who was in Phrygia on the other side of his kingdom, heard that his son Demetrius had been beaten at Gaza, he marched with all his forces to give battle to Ptolemy.  He soon crossed Mount Taurus, the lofty range which divides Asia Minor from Syria and Mesopotamia, and joined his camp to that of his son in Upper Syria.  But Ptolemy had gone through life without ever making a hazardous move; not indeed without ever suffering a loss, but without ever fighting a battle when its loss would have ruined him, and he did not choose to risk his kingdom against the far larger forces of Antigonus.  Therefore, with the advice of his council of generals, he levelled the fortifications of Acre, Joppa, Samaria, and Gaza, and withdrew his forces and treasure into Egypt, leaving the desert between himself and the army of Antigonus.