Mali is founded by Sundiata in 1235, after the decline and the collapse of Ghana. West Africa remained under Mali control for centuries. Then the Songhai rose to power.
Songhai is founded by Sunni Ali and defeated the Malis, but later got conquered by Moroccans who had guns against the African bows.
Muhammad Askia is the one who made Songhai a state rather than just a tribal kingdom.
Both empires took advantage and prospered through the gold-salt trade.
One item can be the weapons. Many Europeans gave the natives a bunch of weapons because they had plenty. They even gave them faulty weapons or broken ones because the natives didn't know any better.
Simple machines and man power. Egyptians used complex combinations of simple machines such as pulleys and levers to hoist heavy limestone onto each other. Of course, this also required a good deal of physical strength
