Cambyses had Pythagoras taken to Babylon, with a portion of the Egyptian priesthood, and kept him within the gates.[3] This colossal city, which Aristotle compares to a country surrounded by walls, offered at that time an immense field for observation. Ancient Babel, the great prostitute of the Hebrew prophets, was more than ever, after the Persian conquest, a pandemonium of nations, tongues, and religions, in whose midst Asiatic despotism raised aloft its dizzy tower. According to Persian tradition, its foundation dates back to the legendary Semiramis. She it is who was said to have constructed the monster _enceinte_, over fifty miles in circumference: the Imgur-Bel, its walls on which two chariots ran abreast, its superimposed terraces, massive palaces with polychrome reliefs, temples supported on stone elephants and surmounted by many-coloured dragons. There had followed in succession the series of despots who had brought into subjection Chaldea, Assyria, Persia, a part of Tartara, Judaea, Syria, and Asia Minor. Hither Nebuchadnezzar, the assassin of the magi, had led captive the Jewish people who continued to practise their religion in one corner of the immense city which would have contained London four times over. The Jews had even given the great king a powerful minister in the person of the prophet Daniel. With Balthazar, the son of Nebuchadnezzar, the walls of the old Babel had finally disappeared beneath the avenging hand of Cyrus, and Babylon passed for several centuries under Persian rule. By reason of this series of preceding events, at the time Pythagoras came there, there were three different religions side by side in the high priesthood of Babylon: the ancient Chaldean priests, the survivors of the Persian magi, and the _élite_ of the Jewish captivity. The proof that these different priesthoods were in mutual agreement, on the esoteric side, is found in the part played by Daniel, who, whilst acknowledging the God of Moses, remained first minister under Nebuchadnezzar, Balthazar, and Cyrus.