IN the first centuries of our era the one great power of the world was Rome. All southern Europe bowed beneath the conquering sword of the Romans. Africa and Asia, too, owned their sway. For the Mediterranean, the great trade route of the then known world, was theirs, and the countries bordering upon it became mere provinces of Rome. Even the uttermost islands felt their might, and sailing beyond the “narrow seas,” Cæsar set his hand upon the island of Britain. From the Rhine and the Danube in the north, to the desert of Sahara in the south, from the borders of Wales in the west, to the Euphrates and the Tigris in the east, the empire stretched.