Iberian Union's End on Spanish Trade in Guinea Under King João IV

In the early 17th century the government attempted to force all Guinean trade to go through Santiago, and to promote trade and settlement on the mainland, while restricting the sale of weapons to the locals. These efforts were largely unsuccessful. With the end of the Iberian Union in 1640, King João IV attempted to restrict the Spanish trade in Guinea that had flourished for the previous 60 years. Afro-Portuguese traders and colonists, however, were not in a position to deny the free trade that the African kings demanded, as they had come to rely on European products and goods as necessities. The Portuguese were never able to maintain the monopoly they wanted; the economic interests of the native leaders and Afro-European traders and merchants never aligned with theirs. During this period the power of the Mali Empire in the region was dissipating. The farim of Kaabu, the king of Kassa, and other local rulers began to assert their independence.