The three West African kingdoms commonly referred to as the Ghana Empire, Mali Empire, and Songhai Empire, were powerful and influential during their time. However, they all declined for many of the same reasons, including:
1. Economic decline: The economies of these empires were based on the trans-Saharan trade, which involved the exchange of gold, salt, ivory, and other goods. However, with the introduction of European sea trade and the discovery of new trade routes, the trans-Saharan trade declined, and the empires' economies suffered.
2. Political instability: The empires were often plagued by internal power struggles, civil wars, and conflicts between ruling factions. This weakened their ability to maintain control over their territories and led to the fragmentation of their empires.
3. External pressures: The empires faced external pressures from neighboring states, including raids and invasions, which further weakened their power and influence.
4. Environmental factors: The empires were also affected by environmental factors, such as droughts and famines, which led to food shortages and population decline.
Overall, the decline of these empires was the result of a combination of economic, political, external, and environmental factors, which all contributed to their eventual collapse.