Every hundred years is called a century, but a thing that seems a little strange is this--the hundred years from 500 to 600 is called the _sixth_ century, not the fifth; the hundred years from 600 to 700 is called the _seventh_ century, not the sixth; and so on. Thus 615, 625, 650, and so on are all _seventh_ century. Well, we have now reached the seventh century--the six hundreds, and we are to hear of a man who was to make a change in the whole world. He was neither a Roman nor a Greek nor a Frank nor a Goth nor a Briton. He was neither a king nor a general, but only a-- What do you suppose? A CAMEL-DRIVER! and he lived in a little town called Mecca in far-off Arabia. His name was Mohammed. Mohammed went on an errand for a wealthy Arabian lady, and the lady fell in love with him. Although he was a poor camel-driver and only a servant and she was rich, they were married. They lived happily together, and nothing remarkable happened until Mohammed was forty years old. [Illustration: Map of Saracenic empire showing Mecca, Medina, Constantinople, Tours, Cordova, Bagdad, Jerusalem, also Europe.] Mohammed had been in the habit of going out to a cave in the desert to study and think. One day when he visited this cave he had a dream, or a vision, as it is called when such things happen in the daytime when one is awake. In this vision, so Mohammed said, the angel Gabriel had appeared and told him that God, whom the Arabs called Allah, said he must go forth and teach the people a new religion. So Mohammed went home to his wife and told her what had happened, and she believed his story and became his first follower. Mohammed then went forth as he had been directed and taught his relatives and friends what he said Allah had told him, and they, too, believed what he said and became his followers. But when he set out to teach others, who were not his friends nor relatives, they simply thought him crazy and perhaps dangerous. So they got together and planned to get rid of him--even kill him if necessary. But he heard what they were planning, and so he packed up all his belongings and, with his wife and those who believed in him, left the city of Mecca and fled to the town of Medina, a little way off. This was in 622--Six-Two-Two--and was called the Hegira, which in the Arabic language means “flight.”