Arabic-speaking people have spread Islam into the northern Sahara by 750.
The earliest author to mention Ghana is the Persian astronomer Ibrahim al-Fazari who, writing at the end of the eighth century, refers to "the territory of Ghana, the land of gold".
The Ghana Empire lies in the Sahel region to the north of the West African gold fields and is able to profit from controlling the trans-Saharan gold trade.
The early history of Ghana is unknown but there is evidence that North Africa had began importing gold from West African before the Arab conquest in the middle of the seventh century.
Most of our information about the economy of Ghana comes from merchants, and therefore we know more about the commercial aspects of its economy, and less about the way in which the rulers and nobles may have obtained agricultural products through tribute or taxation.
The empire becomes wealthy because of their trading.
They have an abundant amount of gold and salt.
Al-Bakri noted that merchants had to pay a one gold dinar tax on imports of salt, and two on exports of salt.
Other products paid fixed dues, al-Bakri mentioned both copper and "other goods."
Imports probably include products such as textiles, ornaments and other materials.
Many of the hand-crafted leather goods found in old Morocco may also have their origins in the empire.
The main center of trade is Koumbi Saleh.
The king claims as his own all nuggets of gold, and allows other people to have only gold dust.
In addition to the exerted influence of the king onto local regions, tribute is also received from various tributary states and chiefdoms to the empire's periphery.
The introduction of the camel had played a key role in Soninke success as well, allowing products and goods to be transported much more efficiently across the Sahara.
These contributing factors will all help the empire remain powerful for some time, providing a rich and stable economy that is to last over several centuries.
The empire is also known to be a major education hub.
