The Portuguese impose upon Africans a substantially…

The Portuguese impose upon Africans a substantially increased hut tax in 1856—which for the first time must be paid with currency or trade goods rather than with slaves—to defray the cost of military operations to secure economically strategic points leads.

As a result, many Africans either refuse to pay or flee from areas controlled by the Portuguese.

By 1861, therefore, the Portuguese lack the resources for continued military expansion or economic development, and most of the interior remains in the control of African traders and warriors.