At his peak, in today's money. The only people on that list from nonwhite countries are 1 from India and 1 from Mali. China must have been very socialist for the millennium.
Obama's great-grandfather was in a British Kenya colonialist torture prison, making it ironic that Obama helped torture to death Khadaffi, who held out longer against Europe than any other anti-colonialist in history.
If they were pricing at its peak, wouldn't Paul Allen be equal to Bill Gates? Also, I've never seen Gates' net worth, even adjusted for inflation, that high.
After Allen left (mid-80s?) Gates continued working 25 more years before retiring. So he was paid billions more in stock dividends than Allen. Gates sells them gradually, so as not to disturb the share price, which is why my MSFT hasn't grown for a decade. http://finance.yahoo.com/q/it?s=MSFT
Demonstrates how hard it is to truly quantify "wealth." I live a much richer life than that king did, with the internet, modern medicine, air travel, etc. He probably had sex with a lot more women than me, though. Even if they didn't practice modern hygiene, that still counts for a lot.