failure. Roman law was the greatest and most characteristic achievement of the Romans; it represented the best in their political theory and practice. Justinian's version, with all its weaknesses, was worthy of the Roman legal tradition, and in happier circumstances might have become a symbol of political unity, like the English common law or the American Constitution. As it was, it stirred up no great enthusiasm anywhere in the Empire. Justinian's code had to be modified almost at once in the East in order to meet local conditions and it was not even applied in the West. It was to have incalculable influence on Western thinking six centuries later, but for the moment it was a dead letter.
Even before Justinian's death a new horde of barbarians, the Lombards, were pushing into Italy from the north. They soon overran two-thirds of the peninsula, and though the Empire retained a few fragments of Italian territory its hopes of maintaining a dominant position in the western Mediterranean basin were gone forever. Catastrophe in the East did not come quite so rapidly, but when it struck it was even more devastating. The latent hostility of the Oriental peoples to Graeco-Roman supremacy crystallized around the Arab Empire and permanently separated the southern and eastern shores of the Mediterranean from the civilizations of the north and northeast.
The Arabs, like the Germans, were a small, rather poorly organized group of peoples, who had raided the Empire intermittently for centuries without constituting a real military danger. Nothing shows the weakness of the old Mediterranean civilization in its last days quite so clearly as the fact that these weak border peoples could change the fate of millions with only a slight effort. The results are out of all proportion to the cause unless we realize that the invaders, German or Arab, merely set off a reaction which was already prepared. They were the detonators, but the explosives were already stored up in the Mediterranean basin. The Arabs had probably grown in numbers during the