The earliest written records were provided by the Arabs who developed close contact with West Africa by 800 A.D. After that, West Africans began using Arabic themselves to record their own history. In the middle of the fifteenth century, Europeans began regular contact with West Africa, and they left a wide variety of written sources. While most of these early Europeans were not men of learning, many of their records are still valuable to the student of history. Ghana was already a powerful empire, with a highly complex political and social organization, when the Arabs reached it about 800 A.D. An Arabic map of 830 A.D. has Ghana marked on it, and other contemporary Arabic sources refer to Ghana as the land of gold. From this time on, a thriving trade developed between Ghana and the world of Islam, including the beginnings of a slave trade. However, this early slave trade was a two-way affair. Al-Bakri, a contemporary Arab writer, was impressed with the display of power and affluence of the Ghanaian king. According to him, the king had an army of two hundred thousand warriors which included about forty thousand men with bows and arrows. (Modern scholars know that the real power of the Ghanaian army was due not to its large numbers as much as to its iron-pointed spears.) Al-Bakri also described an official audience at the royal palace in which the king, the Ghana, was surrounded by lavish trappings of gold and silver and was attended by many pages, servants, large numbers of faithful officials, provincial rulers, and mayors of cities. On such occasions, the king heard the grievances of his people and passed judgment on them. Al-Bakri also describes lavish royal banquets which included a great deal of ceremonial ritual. The power of the king, and therefore of the empire, was based on his ability to maintain law and order in his kingdom. This provided the development of a flourishing commerce, and it was by taxing all imports and exports that the king was able to finance his government. The key item in this financial structure was the regulation of the vast gold resources of West Africa, and it was by controlling its availability that the king was also able to manipulate its value. However, after the eleventh century, the Ghanaian empire was continually exposed to harassment from a long series of Arabic holy wars. Over a long period of time, the power of the king was reduced until the empire of Ghana finally collapsed. From its ashes emerged the basis for the creation of a new and even larger empire: the empire of Mali.