Back in the fourteenth century, Mansa Musa was the ruler of a West African Empire and was said to be worth more than double that: around 400 billion dollars by today’s money, accounting for inflation. Such wealth is often hard to imagine, so for context, this figure is the same as the national gross domestic product of Norway. Musa was so wealthy that his lavish gifting crashed a regional gold market for a decade, and quite literally put him and his empire on the map.