This is off the beaten path, but there's been some Twitter conversation recently about "great man" theories of history and how you can, for example, figure out the IQs of historical individuals in the first place.
As it happens, there's a very famous study of historical figures written a century ago by IQ pioneers Catharine Cox and Lewis Terman. They use various ways of estimating IQ without directly measuring it, and if you're interested in how they do it the best bet is to read their book. In short, though, they rigorously investigated childhood precocity, schoolwork, and the nature of later accomplishments to make their estimates.
Cox's original book included 300 historical figures. A complete list is here. I chose 50 fairly randomly for the chart below. Note that the IQs have been adjusted from Cox's original estimates to reflect what they'd be on a modern IQ test rather than on the older scale originally used by Cox.
There are some interesting things here. It's not surprising to find Leibniz and Newton with stratospheric IQs, but who would have guessed a British prime minister would match them?
Byron, Dickens, and Hugo are surprisingly brilliant writers. Ditto for Madame de Staël of salon hosting fame. Beethoven was smarter than I would have guessed, while my personal favorite Benjamin Franklin was less so. Many generals and political leaders (Bolivar, Napoleon, Washington, Lee, Cromwell, Grant) have pretty pedestrian IQs but obviously it didn't matter. IQ might make the mathematician, but not the leader, who needs more than just IQ to succeed.
In case you're wondering just how rare high IQs are, here's a quick summary:
For example, this means there's about one person in the US with an IQ above 190 and perhaps a dozen in the entire world.
On the other hand, if you have a piddling IQ of 145, there are more than 300,000 just like you in the country. Don't get cocky.