Richest man all the time

 Mansa Musa, the ruler of the Mali Empire in the 14th century, is widely considered to be the richest person in history: 

• Wealth

  Musa's wealth came from the Mali Empire's control of the salt trade and gold mining. His empire included parts of modern-day Mali, Senegal, Gambia, Guinea, Niger, Nigeria, Chad, and Mauritania. 
• Spending

  Musa spent his wealth lavishly while traveling, which caused the value of gold in Cairo to drop for over a decade. 
• Net worth

  While it's difficult to quantify Musa's net worth in modern terms, some estimate it to be around $400 billion. 

Other people who have been considered among the richest people of all time include: 

• Joseph Stalin: Some economists consider Stalin to be one of the richest people of all time because of his control of the Soviet Union's economy.

• Mansa Musa^[a] (reigned c. 1312 – c. 1337^[b]) was the ninth^[5] Mansa of the Mali Empire, which reached its territorial peak during his reign. Musa's reign is often regarded as the zenith of Mali's power and prestige, although he features comparatively less in Mandinka oral traditions than his predecessors.

  Musa I
  Depiction of Mansa Musa, ruler of the Mali Empire in the 14th century, from the 1375 Catalan Atlas. The label reads: This Black Lord is called Musse Melly and is the sovereign of the land of the black people of Gineva (Ghana). This king is the richest and noblest of all these lands due to the abundance of gold that is extracted from his lands.[1]
  Mansa of Mali
  Reign	c. 1312 – c. 1337 (approx. 25 years)
  Predecessor	Muhammad[2]
  Successor	Magha
  Born	1280 Mali Empire
  Died	c. 1337 Mali Empire
  Spouse	Inari Konte[3]
  House	Keita dynasty
  Religion	Islam Maliki

  Often described as the richest person in history,^[6] he is known to have been enormously wealthy, described as being inconceivably rich by contemporaries; Time magazine reported: "There's really no way to put an accurate number on his wealth."^[7] It is known from local manuscripts and travellers' accounts that Mansa Musa's wealth came principally from the Mali Empire controlling and taxing the trade in salt from northern regions and especially from gold panned and mined in Bambuk and Bure to the south. Over a very long period Mali had created a large reserve of gold. Mali is also suspected to have been involved in the trade in many goods such as ivory, slaves, spices, silks, and ceramics. However presently little is known about the extent or mechanics of these trades.^[8][9] At the time of Musa's ascension to the throne, Mali in large part consisted of the territory of the former Ghana Empire, which Mali had conquered. The Mali Empire consisted of land that is now part of Guinea, Senegal, Mauritania, the Gambia, and the modern state of Mali.

  Musa went on Hajj to Mecca in 1324, traveling with an enormous entourage and a vast supply of gold. En route, he spent time in Cairo, where his lavish gift-giving is said to have noticeably affected the value of gold in Egypt and garnered the attention of the wider Muslim world. Musa expanded the borders of the Mali Empire, in particular incorporating the cities of Gao and Timbuktu into its territory. He sought closer ties with the rest of the Muslim world, particularly the Mamluk and Marinid Sultanates. He recruited scholars from the wider Muslim world to travel to Mali, such as the Andalusian poet Abu Ishaq al-Sahili, and helped establish Timbuktu as a center of Islamic learning. His reign is associated with numerous construction projects, including a portion of Djinguereber Mosque in Timbuktu.