Why were the Portuguese unable to coerce West and Central African stat

Why were the Portuguese unable to coerce West and Central African states in the 1400s into accepting a subjugated economic and political relationship?

What political, military, and economic advantages did these Western and Central African states possess that enabled them to resist the efforts at political conquest and economic subjugation by the Portuguese? What alternative approach to a military-based colonial conquest did the Portuguese implement when it became clear that political conquest would be untenable?

ANSWER
Answer: An ideal answer will:
1. Discuss how economic trade by specific Central African and West African states generated wealth in terms of gold, ivory, slave trade, silks, and other fine goods.
2. Discuss how the centralized government of several of these Central African and West African states helped them mobilize resistance to Portuguese aggression.
3. Discuss how both the centralized government and substantial wealth from trade of these Central African and West African states led to military power that permitted West Africans to resist the initial and subsequent Portuguese efforts at political conquest and economic subjugation.
4. Discuss how the Portuguese’s inferior canoes, fewer fighters, and unfamiliarity with unchartered and hostile African rivers put them at a military disadvantage in their initial attempts at conquest of these Central African and West African states.
5. Discuss how the Portuguese recognized as early as 1456 that their military disadvantages meant that it would be preferable to negotiate treaties of peace and commerce with African rulers of several states.
6. Write a concise and effective conclusion.