Elite chess players can be strange too. Kasparov popularized this wacky conspiracy theory.

New chronology (Fomenko)

The new chronology is a pseudohistorical conspiracy theory proposed by Anatoly Fomenko who argues that events of antiquity generally attributed to the ancient civilizations of Rome, Greece and Egypt actually occurred during the Middle Ages, more than a thousand years later.

[...]

Fomenko's historical ideas have been universally rejected by mainstream scientists, historians, and scholars, who brand them as pseudohistory, pseudoarchaeology, and pseudoscience, but were popularized by former world chess champion Garry Kasparov. Billington writes that the theory "might have quietly blown away in the wind tunnels of academia" if not for Kasparov's writing in support of it in the magazine Ogoniok.

Kasparov met Fomenko during the 1990s, and found that Fomenko's conclusions concerning certain subjects were identical to his own regarding the popular view (which is not the view of academics) that art and culture died during the Dark Ages and were not revived until the Renaissance.

Kasparov also felt it illogical that the Romans and the Greeks living under the banner of Byzantium could fail to use the mounds of scientific knowledge left them by Ancient Greece and Rome, especially when it was of urgent military use. Kasparov does not support the reconstruction part of the new chronology.