In this concluding chapter, therefore, we shall confine our attention to Alexandria and the court of the Ptolemies, whither the centre of gravity of the Greek world trended after the fall of Greek independence and the decline of Athens. Its great founder seems to have shown prophetic insight in his selection of the spot on which to build the city that should bear his name, and the supremacy of that city was assured when Alexander by his conquests opened up the Orient to Greek commerce; but the greatest good fortune of Alexandria lay in obtaining a ruler of the ability and insight and energy of Ptolemy Soter. Ptolemy, the son of Lagus and Arsinoe, had grown up with Alexander as one of his playfellows, and later became one of his most trusted, though not most prominent, generals. There is a story that, before her marriage, Arsinoe was a mistress of Philip, and that Ptolemy was in truth the half-brother of Alexander; but there is no testimony to substantiate the tradition, unless it be found in Ptolemy's likeness to Philip in intrigue and governing power. During the stormy years following the death of Alexander, Ptolemy, alone of the generals, seems to have preserved his mental balance; and instead of entering into the struggles of his rivals for world-empire, he preferred to acquire as his secure dominion the province of Egypt, so easily defensible, and separated from the contestable ground of opposing nations. The policy of the first Ptolemy moulded the history of Egypt and the destinies of Hellenism. He surrounded himself with Greeks, so that they became the dominant faction in the government and determined the tone of court society. He gave religious freedom and large liberty in other respects to the Egyptians, so that they became supporters of the dynasty. By the foundation of the Museum, or University, of Alexandria, he made his capital the literary centre of the new era and attracted to his court learned men from all parts of the world. Greek became the language of the court, and Greek culture and manners there prevailed. Mahaffy graphically describes the brilliant court life of Alexandria under Soter and his successors: