Everybody knows the story of Mansa Musa accidentally destroying the economy of various cities on his way to Mecca due to super generous gift giving. But how did he obtain such a massive amount of wealth? I was under the impression that the most lucrative trade in his time was traveling along the silk road through the Levant, Iraq and Persia, not down through Mali. Was there some huge trade going on in Mali that I'm not aware of? According to wikipedia he built up Timbuktu into a very wealthy trade hub, but only later in his life, after his pilgrimage.
Also, how did his wealth compare to other rulers at the time? Was he actually insanely wealthy, or just insanely generous?
One thing many people don't understand is how important a commodity salt is. It makes food taste better and, in hotter climates, is essential for hydration. Prior to the modern era when salt mining became industrial operations with huge machines doing most of the work, salt was very difficult to get. It was either mined by hand in deplorable conditions, usually by slaves, or made through evaporating sea water.
The importance and scarcity of salt thus led to the development of trade between West Africa, where gold was relatively abundant, and North Africa, where salt came from. Camel caravans would cross the Sahara to do their trade, and Timbuktu, because of it's position smack-dab in the middle between the gold fields and salt mines, became very wealthy from this trade.