The lustre of Arab culture, especially as displayed in the large cities of Babylonia, the central province, arose from a liberal intermixture of Persian and Arab elements. In some of these cities Persian was actually spoken by the bulk of the population, at least in the early centuries of Islamism. The influence of Byzantine civilisation on that of Arabia, though far slighter, should not be overlooked. For centuries the upper classes of Babylonia, luxurious and often frivolous as they were, maintained a high level of intellectual activity. The gift of expressing oneself in elegant Arabic with Persian charm and Persian wit was held in the highest esteem. Similar centres of superior culture existed in other Arabic-speaking countries right across to Spain, and for a time even in Sicily. Through all the wide domains of Islam men travelled much, partly to complete their education and acquire the polish of the man of the world, partly for pure love of travel and thirst of adventure. Public and private societies of _beaux-esprits_ and scholars existed in every town of any importance. A brisk trade by land and sea did much to insure the rapid interchange of commodities between regions the most remote, even such as lay far beyond the pale of Islamism, and the result of trade was the accumulation of vast wealth in the great cities. Thither also flowed the taxes levied _per fas et nefas_, upon the inhabitants of the plains. Of course there was no lack of misery in the great cities of the Arab world, any more than in those of Europe and America at the present day. ARAB RECORDS AND TRADITIONS The Moslems very early began to hand down biographical records of the prophet, at first by oral, but in the main authentic tradition. More important still to the whole Moslem world was the transmission and collection of precepts covering the whole of life, which pretended to be preserved in the exact form in which they had been uttered by the prophet or made current by his act.[24] It is of the utmost advantage to us to-day that the history of Mohammed’s successors, of their great conquests, and of the empire, follows so immediately upon his own. The several records used to be handed on with the names of those who vouched for them, from the first eye-witness down to the last teller of the tale, variations of statement being placed close side by side. In this way narratives told from the point of view of absolutely different parties have come down to us side by side, many of them dealing with the most important events of the first centuries of Islam, so that historical criticism is frequently in a position to ascertain the main features of what really took place with far greater certainty than if the Arabs themselves had proceeded to draw up a regular history and had manipulated their authorities in their own fashion. The tradition of the deeds and adventures of the ancient heroes of Arabia, too, was carefully cherished, and much of it has come down to us.