Savanna kingdoms refer to a series of powerful states that developed in the grassland regions of Sub-Saharan Africa, particularly during the medieval period. These kingdoms, such as Ghana, Mali, and Songhai, thrived due to their strategic locations for trade across the trans-Saharan routes, allowing them to control commerce involving gold, salt, and other goods. The wealth generated from trade facilitated advancements in culture, architecture, and political organization within these societies.