Corrected entry: In both instances where William crossed the English Channel, it was on a chain ferry. It is highly unlikely that any individual, or even a group of individuals could afford the 20-odd miles of chain it would require. To top it off, when they return to England, their landfall is made at London, which would require yet another 20-odd miles of chain to take them up the Thames.
Corrected entry: In the scene where Jocelyn turns the scarf for William in her hands you can see that it is a light yellow one without embroidery. In a later scene where Christiane brings the scarf to William it is another one with yellow embroidery on it.
Corrected entry: William uses Sir Ector's armor, which still has his device (the emblem on the shield) painted on it. Since Sir Ector was a regular on the jousting circuit, other knights and nobles would have been able to identify the device and expose 'Sir Ulrich von Lichtenstein' as an imposter.
Corrected entry: The Royal Guards who arrested William wore a Spanish helmet. This helmet actually didn't became in fashion until the time of Elizabeth the First, 200 years later.
Corrected entry: Before the companions reach Paris, there is a camera shot which includes the Eiffel Tower. It would be factually inaccurate to place both Chaucer and the Eiffel Tower in the same place at the same time seeing as though Chaucer was around centuries before the Eiffel Tower was constructed to mark the centenial year of French Independence, in 1889.
Corrected entry: In the first jousting scene after William is given his new armor from Kate, Roland and Wat lie to him about his next opponent having raised his country's taxes to pay for the tournament and then cut to a shot of his opponent trying to mount his horse. The problem is he mounts the horse from the wrong side. The knight should have mounted from the left side but can plainly be seen mounting from the right. Mounting from the left is an equine tradition dating back to the times of knights and is done because the sheath of a sword is worn on the left and gets in the way if they try to mount from the right. Surely a knight would have known this.
Corrected entry: When William is facing Adhemar in the final match, Adhemar almost destroys Williams' frontal armor's right side (you can even see it is folded in two). When they are preparing for the second round his armor is intact again. When the second round begins, back to the destroyed armor.
Corrected entry: In the opening sequence when the captions come up "In medieval times, a new sport emerged...", we see a knight being knocked off his horse in a joust. The knight being knocked off is wearing Heath Ledger's original suit of armor. (You can tell by the shield he is holding - it has the three phoenixes on it.)
Corrected entry: The redheaded peasant Wat constantly carps on about not having enough money to eat yet he wears a rather modern very thin silver chain throughout the entire film. Perhaps he could have pawned that to buy some Tansy cakes with peppermint cream?
Corrected entry: When there was a flashback to when William was a child, the child actor used looked exactly like the adult actor...with one major flaw: The boy had sparkling blue eyes, the man, dark brown.
Corrected entry: During the pub scene when the French drunkards are challenging Chaucer and the others to bet that Ulrich will not win the tournament, Wat throws a fit and calls one of them Quasimodo. Quasimodo is a character from "The Hunchback of Notre Dame" by Victor Hugo, published in 1831 - about 500 years later. Even if Quasimodo had been based on a real person, the story took place in the 15th, not 14th, century.
Corrected entry: When Heath and his crew are entering into the World Championships, we hear the crowd begin to chant Ulrich's name, but if you look at the crowd in the background, they are simply yelling, and their mouths are not in sync with the chanting at all.
Corrected entry: At the end of the film, everyone stands up and starts to cheer for William, including Jocelyn and John. The camera focuses on them, and then goes back to William, and then zooms in on to them again. They are still standing. Then the camera zooms out, and it has gone back enough so we can see the stand, all the way to the Prince's seat. Jocelyn is running down the steps. But John is seated again.
Corrected entry: When knights jousted, they would only ride on the left-hand side of the barrier as it was easier to hit their opponent. In this film, they only seem to right ride on the right-hand side of the barrier.
Corrected entry: During the last joust of the movie William is injured but when the joust is finished he hops right over the fence using his injured arm as support, and appears unaffected by the injury.
Corrected entry: During the sword fight in the first tournament you can clearly see that William's armour has a repaired breast plate. This damage does not happen till later and is then taken to various armourers to be repaired.
Corrected entry: In the first jousting scene, when William is masquerading as Sir Ector, the armor he's wearing has a metal hook device attached which serves as a cradle to hold the lance steady. Roland and Wat even exort William to 'get it in the cradle', as he rides toward his opponent. William finally cradles the lance at the last second and all goes well. Then, in every subsequent jousting scene, no knight has a cradle device on their armor. Not even William, whose cradle has disappeared, never to be seen again.
Corrected entry: At the end of the last jousting scene, William is stabbed in the shoulder with a lance, but there's no hole in his shirt, only blood.
Corrected entry: When they finally arrive in London for the world championship jousting match, there's a scene showing London Bridge and the city as they would have existed back then. But if you look toward the horizon, you can see the outline of the "London Eye", the giant ferris wheel built in 1998. It's to the upper right of the screen.
Corrected entry: When Kate the blacksmith offers to make William a brand new suit of armor, he asks what that will cost him. Kate says: "Just take me as far as Paris." When they eventually arrive in Paris later in the movie, no explanation is ever given why Kate wanted to go there. Then, when the group leaves Paris to head for the World Championships in London, Kate is still with them.