The Richest Man in History - Mansa Musa

http://www.barrons.com/articles/who-was-the-richest-person-who-ever-lived-1469247020?mod=bol-ampush

So while we cannot translate Mansa Musa’s wealth into modern terms with any specificity, Forbes Magazine’s researchers had no hesitation in calling him the richest man who ever lived, and ballparked his modern-day net worth at $400 billion.