10. Osman Ali Khan, Asaf Jah VII– peak net worth: $230 billion
The last ruler of Hyderabad in India, Khan was absolute leader of the princely state from 1911 and 1948, and for a good part of the 20th century he was known as the richest man in the world with an estimated fortune of $2 billion by the early 40s. This is the equivalent of 2% of the US economy or around $230 billion today.
9. Tsar Nicholas II of Russia – peak net worth: $300 billion
Ill-fated Nicholas Romanov ruled over the Russian Empire from 1894 to 1917, during which time he had full access to the nation’s coffers, making him one of the richest monarchs in history. Not one to redistribute his wealth, a 1916 estimate of the tsar’s personal fortune equates to $300 billion in today’s money.