Why did the Kingdom of Ghana become prosperous and powerful

The kingdom of Ghana Rose to power by gaining control of the trans-Saharan gold and salt trade. Agricultural villages in the savanna produced a surplus, in which the surplus food began to be traded for products from other villages. Gradually, a trade network was created that linked the savanna to the Sahara. Gold and salt was dominate in Sahara trade. West Africa had a substantial amount of gold in which they traded for salt, a product important to human health but scarce in the savanna. By A. D. 800, the kingdom of Ghana was created and located in the fertile, broad "V" made by the Niger and Senegal rivers in present-day Mali, where the king controlled gold-salt trade routes and all goods entering and leaving Ghana land. So great was the flow of riches that the King's court's attire was described as composed of gold and silver from the pages' armor to the dogs' collars.