Until the Portuguese established firm control over their territory, the Ovimbundu – particularly those of the major kingdoms of Bailundu (to the northwest), Bihe (to the northeast), and Wambu (in the center) – played important roles as intermediaries in the slave, ivory, and beeswax trades, acting as carriers, entrepreneurs, and raiders. With the decline of the slave trade in the last decades of the nineteenth century, the entrepreneurs among the Ovimbundu turned to the rubber trade, abandoning the warfare and raiding that had hitherto been integrally related to their economic activities. The rubber slump at the beginning of the twentieth century, the end of the de facto autonomy of their kingdoms not long after, and the displacement of Ovimbundu traders by the Portuguese forced these people to turn to cash-crop agriculture. (The men had hitherto had little involvement with cultivation; in fact, the women continued to be responsible for the cultivation of subsistence crops.)