The best means of realising the extent of the Roman Empire in or about the year 64 is to glance at the map. It will be found to reach from the Atlantic Ocean to the Euphrates, from the middle of England - approximately the river Trent - to the south of Egypt, from the Rhine and the Danube to the Desert of Sahara. The Mediterranean Sea is a Roman lake, and there is not a spot upon its shores which is not under Roman rule. In round numbers the empire is three thousand miles in length and two thousand in breadth. Its population, which, at least in the western parts, was much thinner then than it is over the same area at present, cannot be calculated with any accuracy, but an estimate of one hundred millions would perhaps be not very far from the mark...