I know Jeff Bezos is considered the richest known person but there is a lot of hidden wealth in the world.
I've heard the following people may actually be trillionaires:
Putin
Oil Saudis
Rothschild family
If anyone has decided to hide their wealth, then its none of our business cause they dont want it to be anyones business, so they have decided to keep it secret. As of now, the only person that is known by the whole world to be the richest man ever is simply Jeff Bezos. When others are ready to come through prove that they are the richest, then the world will believe them.