A Photograph of Mansa Musa, King of Mali on a map of North Africa circa 1375. (Photo by Fotosearch/Getty Images)

You've probably never heard of him, but Mansa Musa is the richest person ever.

According to Forbes, the Mexican telecom giant's net worth is $69 billion. Slim edges out the world's second wealthiest man, Bill Gates, who is worth $61 billion, according to Forbes.

Some of the oldest fortunes in question date back 1,000 years. No. 7 on the list, for example, is William the Conqueror. The illegitimate son of the Duke of Normandy, William lived between 1028-1087 and gained infamy for invading and seizing England in 1066.

According to the Encyclopedia Brittanica, when Musa died sometime in the 1330s, he left behind an empire filled with palaces and mosques, some of which still stand today. But the emperor really turned historic heads for the over-the-top extravagances of his 1324 pilgrimage to Mecca.

The trip, which he embarked up on during the 17th year of the monarch's glittering reign, was hosted by the leaders of both Mecca and Cairo and apparently was so brilliant, it "almost put Africa’s sun to shame."

Musa's wealth was a result of his country's vast natural resources. The West African nation was responsible for more than half of the world's salt and gold supply, according to Net Worth. Of course, the entry also notes that the fortune was also fleeting. Just two generations later, his net worth was gone -- wasted away by invaders and infighting.

As The Independent points out, while the numbers bandied about by this newest list are shocking, many aspects of the run-down aren't surprising: there are no women included, for example, and only three of the richest men are still alive today. Americans dominate the list, however, taking 14 of the 26 spots, including slots two and three.

The "poorest" man on the list is Warren Buffet, who had a peak net worth of $64 billion. Buffet, a noted philanthropist, has since given billions of his fortune away, and Forbes now lists his net worth at closer to $44 billion.

And the rest:

21. Jay Gould (railroad tycoon, 1836-1892) $71 billion

22. Carlos Slim (business magnate, 1940- ) $68 billion

23. Stephen Van Rensselaer (land owner, 1764- 1839) $68 billion

24. Marshall Field (Marshall Field & Company founder, 1834-1906) $66 billion

25. Sam Walton (Walmart founder, 1918-1992) $65 billion