Which outside group did tribes in Africa encounter first?

The first outside group that many tribes in Africa encountered were European explorers and traders, beginning in the late 15th century. Notable figures include Portuguese explorers like Vasco da Gama, who sought new trade routes to Asia. These encounters often involved trade, but they also led to the establishment of colonial interests and significant cultural exchanges. Additionally, the transatlantic slave trade significantly impacted many African societies from the 16th century onwards.