Shortly after the year 400 the poet Prudentius wrote that the Roman Empire had never been more flourishing nor so happy. All the evidence that we possess tends to show that it seemed eternal and impregnable to its citizens. It was impossible for them to conceive of their life without it. The Western provinces formed a single, carefully administered state, covering modern England, France, the Netherlands, Western Germany, Portugal, Spain, Italy, North Africa, and part of the Balkans. All were joined by a common culture, a common way of life, the common use of Latin. There were close economic links with the Eastern provinces of the Empire grouped round the other end of the Mediterranean. Here, Greek was the common language instead of Latin and great cities like Antioch and Alexandria had come to play roles paralleled today by New York and Chicago.

In the year 400, the young Emperor in the East was brother to the Emperor of the West and was thought of as his partner in a single sovereignty. The partnership seemed indissoluble. In the words of the greatest of fourth-century poets, ‘All Roman subjects were citizens of a single city, children round a single hearth’. The Roman way of life was prized as the common heritage of all free men. During the last forty years there had been a great increase in legislation in the West. For the most part, it had been enlightened and progressive and it regulated to the smallest detail the activities of every citizen.