But perhaps the names of the old towns of the old world tell us the best stories of all. The greatest city the world has ever seen was Rome, and many scholars have quarrelled about the meaning of that great name. It seems most likely that it came from an old word meaning "river." It would be quite natural for the people of early Rome to give such a name to their city, for it was a most important fact to them that they had built their city just where it was on the river Tiber. One of the best places on which a town could be built, especially in early days, was the banks of a river, from which the people could get water, and by which the refuse and rubbish of the town could be carried away. Then, again, one of the chief things which helped Rome to greatness was her position on the river Tiber, far enough from the sea to be safe from the enemy raiders who infested the seas in those early days, and yet near enough to send her ships out to trade with other lands. Thus it was, probably, that a simple word meaning "river" came to be used as the name of the world's greatest city. Others among the great cities of the ancient world were founded in a quite different way. The great conqueror, Alexander the Great, founded cities in every land he conquered, and their names remain even now to keep his memory alive. The city of _Alexandria_, on the north coast of Africa, was, of course, called after Alexander himself, and became after his death more civilized and important than any of the Greek cities which Alexander admired so much, and which he tried to imitate everywhere. Now Alexandria is no longer a centre of learning, but a fairly busy port. Only its name recalls the time when it helped in the great work for which Alexander built it--to spread Greek learning and Greek civilization over Europe and Asia. Another city which Alexander founded, but which afterwards fell into decay, was _Bucephalia_, which the great conqueror set up in the north of India when he made his wonderful march across the mountains into that continent. It was called after "_Bucephalus_," the favourite horse of Alexander, which had been wounded, and died after the battle. The town was built over the place where the horse was buried, and though its story is not so interesting as that of Alexandria, as the town so soon fell into decay, still it is worth remembering.