It preferred them to stay at its colonies of Benguela and Luanda on the coast, while the native pombeiros led caravans into the interior to buy slaves.
During their trips into the interior, the pombeiros resided at fortified marketplaces called feiras, to which Africans from beyond the frontier would come to sell produce, wares and slaves.
Slaves from Kazembe could be traded to the Lunda, who in turn sold them to the Imbangala, who brought them to the pombeiros at Kasanje.
This way the human capital of Kazembe made its way to the Atlantic, whereas the ivory of the kingdom was sent east to the Portuguese feira at Tete for the Indian Ocean trade.
In 1806, two pombeiros named Pedro João Baptista and Amaro José travelled from Luanda as far as Tete and back, but the journey took them over four years.