No, it's not the Tatas, Birlas or Ambanis, it's Osman Ali Khan, the last Nizam (or ruler) of Hyderabad. 

According to a new inflation-adjusted list of the world's richest people of all time, the Nizam, who ruled Hyderabad between 1886-1967, was ranked sixth with $236 billion. 

Osman Ali Khan died in 1967 at age of 80. 

Mansa Musa I of Mali ? the obscure 14th century African king - was named the richest person in all history, British newspaper 'The Independent' reported today. 

With an inflation adjusted fortune of $400 billion, Mansa Musa I would have been considerably richer than the world's current richest man, Carlos Slim, who ranks in 22nd place with a relatively paltry $68 billion. 

The list, compiled by the Celebrity Net Worth website, ranks the world's 24 richest people of all time. The list advertises itself as the top 25, but only 24 names appear in the list. 

Although the list spans 1,000 years, some aspects of wealth appear consistent throughout history; there are no women on the list, only three members are alive today, and 14 of the top 25 are American. 

The list uses the annual 2199.6 per cent rate of inflation to adjust historic fortunes? a formula that means $100 million in 1913 would be equal to $2.299.63 billion today. 

Mansa Musa I ruled West Africa's Malian Empire in the early 1300s, making his fortune by exploiting his country's salt and gold production. Second on the list are the Rothschild family, whose descendants are still among the richest people on the planet. 

Starting out in banking in the late 18th Century, Mayer Amschel Rothschild's finance house accumulated a total wealth of $350 billion. 

Meanwhile, John D Rockefeller, third on the list, is the richest American to have ever lived, worth $340 billion in today's US dollar at the time of his death in 1937. 

In comparison, the poorest man on the list is 82-year-old Warren Buffett, who at his peak net worth, before he started giving his fortune to charity, was $64 billion.