Cross-cultural encounters between the people of Benin and Europeans, specifically the Portuguese, are displayed in a number of the Benin Bronzes. These bronze plaques and figures depict rulers and warriors of the Kingdom of Benin dressed in ornate battle gear. They also often show stylized Europeans depicted in much less detail.
We cannot be certain exactly what was meant by depicting the Portuguese in these works of art. What they do tell us is that the West African artists who made these pieces and the wealthy rulers who likely commissioned them wanted to make a statement about the exchanges occurring between the different cultures. The African figures are typically depicted along with trappings of battle and the Europeans are shown ready to trade. This suggests a willingness among the Benin rulers to engage in commerce with the Portuguese, backed up by the threat of their military if the foreigners should try to take advantage of them.
In short, the Benin Bronzes illustrate an uneasy commercial alliance between vastly different cultures. The bronzes are likely intended to display the power of the Kingdom of Benin, but also show their willingness to engage with the Portuguese as long as these outsiders recognize the power of Benin.
(I have included an image of one of these bronze works. Note the two smaller Portuguese figures in the upper center part of the plaque.)