Charles Xavier - Professor X - may be the leader of the X-Men and the founder of Xavier's School for Gifted Youngsters, but the telepath certainly isn't immune to the odd mistake - or ten.

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The iconic superhero has been played by both James McAvoy and Patrick Stewart (the latter of which recently returned to the role in Doctor Strange in the Multiverse of Madness). Professor X regularly saves the day, but his faith in his frenemy Erik Lensherr (Michael Fassbender) and monitoring of his old friend Raven (Jennifer Lawrence) often result in the English hero looking foolish.

Letting Fame Get to his Head ('X-Men: Dark Phoenix')

Dark Phoenix James McAvoy Professor X

X-Men: Dark Phoenix introduced audiences to a world that was much more appreciative of the X-Men and mutant-kind in general than fans ever saw before. Not only were the X-Men seen as heroes, but Professor X had a direct line to the President, allowing the group to respond immediately to any issues the country may face.

This newfound fame and success distorted Charles' moral compass. He quickly became more interested in his own reputation than the well-being of his students, a move that spits in the face of all the principles of Xavier's School for Gifted Youngsters.

Underestimating Stryker ('X2: X-Men United')

X2 Patrick Stewart

Given his incredible intellect and telepathic abilities, it isn't often that we see Professor X wander into a trap. Yet, in X2: X-Men United, that's precisely what happened. The elderly professor was captured by William Stryker (Brian Cox) while visiting his old foe Magneto (Ian McKellan) in a plastic-free jail cell.

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It's somewhat surprising that Charles would underestimate Stryker, especially given that he knew exactly what the man put Wolverine (Hugh Jackman) through. Thankfully, Charles' loyal team of students was on hand to rescue him. Wolverine continues to be there for Charles, with Jackman returning to his iconic role in the highly-anticipated Deadpool 3.

Lying to Jean Grey ('X-Men: Dark Phoenix')

Jean Grey with fire cracks on her face in the movie Dark Phoenix.
Image via 20th Century Fox

Charles has never quite known how to handle Jean Grey's (Sophie Turner) extraordinary powers. Though he cares greatly for her, he decided the best way to protect her is to shield her from the truth. The truth is that, though Jean believes she accidentally brought about the death of her parents during a flare-up of her powers, her father survived.

Xavier kept Jean away from him because he blamed her for the death of his wife and no longer wanted to see her. This realization caused Jean to unravel, and brought about a level of chaos that Charles could never have predicted.

Trying to Control Jean ('X-Men: The Last Stand')

Famke Janssen as Jean Grey using her powers in X-Men: The Last Stand
Image via 20th Century Studios

When a young Charles Xavier and Erik Lensherr visited the childhood home of Jean Grey (Famke Janssen), they experienced a power unlike anything they had ever seen before. Rather than attempting to nourish Jean's power and turn her into the greatest hero the world has ever seen, Charles instead placed a series of psychic barriers around her brain, attempting to limit her power.

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This is arguably the biggest mistake Charles makes in any of the X-Men movies, as it actually results in the characters' death. With The Phoenix unleashed, Jean used all of her power to destroy her old mentor, obliterating him and leaving nothing behind. The post-credits scene may suggest Charles isn't actually dead, but that has never been expanded upon, so it's hard to be sure.

Wiping Moira's Memory ('X-Men: First Class')

The X-Men looking in the same direction in X-Men: First Class.

The decision to wipe Moira MacTaggert's (Rose Byrne) memory during the finale of X-Men: First Class may not have any world-ending consequences, but it certainly has a significant effect on the rest of Charles' life. Moira never shared her co-worker's opinion that mutants were a threat.

In fact, she admired Charles' powers and the way he fought to protect other mutants. The feelings they shared for one another were genuine, and Charles may well have had a much happier life if he hadn't wiped her memory, allowing them to have a real shot at the happy-ever-after they each deserve.

Putting his Students in Danger ('X-Men: Dark Phoenix')

The X-Men in their jet plane

Of course, given the nature of the X-Men team, Charles cannot keep his students away from dangerous situations. They often have to rush into frightening situations armed only with their wits and their powers to make it out alive.

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The space rescue scene in X-Men: Dark Phoenix, however, is something Charles should have pulled his team away from. The risk was far too great for any of them to contain, and the entire team could have been lost if Jean wasn't able to absorb the cosmic energy. Although that brings about an entirely new danger for the team.

Forcing Raven to Hide Her True Self ('X-Men: First Class')

Jennifer Lawrence playing Mystique/Raven Darkhölme in the 2014 movie X-Men: Days of Future Past
Image via 20th Century Fox

X-Men: First Class showed the first meeting between Charles Xavier and Raven, a young girl with the ability to shapeshift to look like anyone. Her natural form, however, is quite far from the norm.

Her blue skin and red hair would be enough to draw the attention of the world, and, given that Charles is keen to keep the existence of mutants hidden, he encourages Raven never to show her true form. This pushes her towards Magneto, who thinks her natural form is beautiful and doesn't understand why she would ever hide from the world.

Trusting Magneto ('X-Men: Days of Future Past')

Magneto and Peter standing still in X-Men: Days of Future Past.

Magneto and Charles may have fought side by side during the Cuban missile crisis, but soon after, Magneto revealed that he was not happy just to protect the mutants; he also wanted to punish the humans for turning against them. Given this insight, Charles' decision to later break Magneto out of jail in X-Men: Days of Future Past is a little baffling.

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Once again, Erik initially fights alongside Charles but quickly becomes concerned with showing the world the might of the mutant race. He is not fighting to save Mystique; if anything, he's happy for her to die. Instead, he's fighting to prove that the mutants are the dominant race and should have the power that reflects that. Not your wisest move, Charles.

Giving Up On Himself ('X-Men: Days of Future Past')

Charles Xavier, James McAvoy & Sir Patrick Stewart

Ten years after the injury that changed his life forever, we meet a version of Charles Xavier, who has given up on himself entirely. The doors to Xavier's School for Gifted Youngsters have been closed forever, and the professor seems happy to merely drink his life away. Hank's (Nicholas Hoult) serum allows him to walk again but in exchange for his powers, meaning he is unable to use Cerebro to track down mutants who need his help.

It could be argued that this is the professor's biggest mistake as the world needs Charles Xavier, and without his influence, mutants would never be accepted by the rest of the world.

Underestimating the Scarlett Witch ('Doctor Strange in the Multiverse of Madness')

Patrick Stewart playing Professor X/Charles Xavier in the 2022 movie Doctor Strange in the Multiverse of Madness
Image via Walt Disney Studios Motion Picture

Ok, so this isn't an X-Men movie, but we're counting it because it features a whopping mistake from Professor X. Though he and the rest of The Illuminati have so far kept the world safe from the threats it has faced, they don't listen to the warning given to them by Doctor Strange (Benedict Cumberbatch).

Rather than prepare for the arrival of the Scarlett Witch, they waste time bickering with Doctor Strange leaving them exposed and vulnerable. Professor X comes the closest to stopping the villainous character by trying to free Wanda Maximoff (Elizabeth Olsen) from the corner of her mind that the Scarlett Witch has trapped her in. He almost succeeds, but the Scarlett Witch proves to be too powerful, eventually overpowering Charles and snapping his neck, bringing a brutal end to the life of one of the world's greatest heroes.

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