In the fortieth century before our era, the Sumerians had entered Mesopotamia. They were soon afterwards overpowered by the Akkadians, one of the many tribes from the desert of Arabia who speak a common dialect and who are known as the “Semites,” because in the olden days people believed them to be the direct descendants of Shem, one of the three sons of Noah. A thousand years later, the Akkadians were forced to submit to the rule of the Amorites, another Semitic desert tribe whose great King Hammurabi built himself a magnificent palace in the holy city of Babylon and who gave his people a set of laws which made the Babylonian state the best administered empire of the ancient world. Next the Hittites, whom you will also meet in the Old Testament, overran the Fertile Valley and destroyed whatever they could not carry away. They in turn were vanquished by the followers of the great desert God, Ashur, who called themselves Assyrians and who made the city of Nineveh the center of a vast and terrible empire which conquered all of western Asia and Egypt and gathered taxes from countless subject races until the end of the seventh century before the birth of Christ when the Chaldeans, also a Semitic tribe, re-established Babylon and made that city the most important capital of that day. Nebuchadnezzar, the best known of their Kings, encouraged the study of science, and our modern knowledge of astronomy and mathematics is all based upon certain first principles which were discovered by the Chaldeans. In the year 538 B.C. a crude tribe of Persian shepherds invaded this old land and overthrew the empire of the Chaldeans. Two hundred years later, they in turn were overthrown by Alexander the Great, who turned the Fertile Valley, the old melting-pot of so many Semitic races, into a Greek province. Next came the Romans and after the Romans, the Turks, and Mesopotamia, the second centre of the world’s civilisation, became a vast wilderness where huge mounds of earth told a story of ancient glory. [Illustration: THE HOLY CITY OF BABYLON] MOSES THE STORY OF MOSES, THE LEADER OF THE JEWISH PEOPLE Some time during the twentieth century before our era, a small and unimportant tribe of Semitic shepherds had left its old home, which was situated in the land of Ur on the mouth of the Euphrates, and had tried to find new pastures within the domain of the Kings of Babylonia. They had been driven away by the royal soldiers and they had moved westward looking for a little piece of unoccupied territory where they might set up their tents.