Walter Isaacson—whose biography of Musk is due to be released next month—said the world’s richest man seeks inspiration from French emperor and military dictator Napoleon Bonaparte on how to lead.

Napoleon was brought to power in France following a coup in the late 18th century, and established a dictatorship soon afterward.

“[Musk] likes military history,” Isaacson told Axios in an interview published on Monday. “And he believes there are lessons that apply to corporate life. For example, he believes that wherever Napoleon was, that’s where his armies would do best. So [Musk] liked to show up late at night on the assembly lines at Tesla and SpaceX.”

Isaacson, now a history professor at Tulane University, is a former editor of Time magazine and ex-chairman of CNN. He has written biographies of late Apple cofounder Steve Jobs, Leonardo da Vinci, and Albert Einstein.

To conduct research for his upcoming book, Isaacson shadowed Musk for two years, attending meetings and factory visits with him, and spent hours interviewing the Tesla CEO and his friends, family, and coworkers.

Musk told Isaacson during this time that he enjoyed reading and listening to World War I history, and that he listened to a history podcast at night.

In his book, Isaacson recounts an incident where Musk spent an hour at SpaceX’s Boca Chica launch site in Texas where a Starship booster was being built.

“If they see their general on the battlefield, they will be more motivated,” Musk, who is the space exploration firm’s chief executive, reportedly told Isaacson.

Musk added that he had “learned that by reading about Napoleon,” Issacson told Axios.

Fortune reached out to representatives for Musk for comment on Isaacson’s claims.

Musk has previously made headlines for his divisive tactics, building a reputation for taking questionable approaches to people management.

Following his $44 billion Twitter acquisition in October, the company reportedly suffered a wave of resignations after he demanded employees sign an oath to work “long hours at high intensity.”

Last month a former Twitter executive went viral on the platform—now known as X—with a series of revelations about how the company was run under Musk. She described a “culture of fear” where employees were “walking on eggshells around Elon” and were afraid to tell him the truth.

Employees at Musk’s other companies Tesla and SpaceX have also gone public in the past with grievances about the way they were treated at work.

‘Unlikely’ Musk v Zuckerberg battle will go ahead

More recently, Musk—the richest man on earth, worth $222 billion—has been making headlines with his proposed physical face-off against fellow tech billionaire Mark Zuckerberg.

The two tech billionaires had previously agreed to face each other in a cage fight to raise money for charity, but after Musk said he needed an MRI before confirming a date, Zuckerberg said it was “time to move on.”

In a post on Musk’s X platform on Sunday, Isaacson wrote Musk had texted him at 4:44 a.m. CT sharing screenshots of messages allegedly sent between himself and Meta boss Zuckerberg.

According to the text exchange shared on Sunday, Musk asked Zuckerberg to “fight in your Octagon” the following day. It was unclear if there was any response from Zuckerberg.

A Meta spokesperson did not respond to Fortune’s request for comment on the messages.

When asked by Axios about whether he thought the cage fight would go ahead, Isaacson said he “doesn’t make predictions when it comes to Musk, but it seems unlikely.”

“I obviously think that this whole cage match idea is completely ridiculous,” he told the publication.