Factual errors: Despite the claims made at the beginning of the film, factual and historical inaccuracies abound.
Continuity: When the Saxons charge Hadrian's wall, the gate is alternately open/closed between shots.
Anachronisms: The hilts on Lancelot's swords are affixed with Torx fasteners, unavailable in fifth century Britain.
Anachronisms: Guinevere's headdress at the end of the movie is held in place by modern bobby pins.
Audio/visual unsynchronized: When the wood-people trap Arthur and his men with barbed-wire-type enclosures, the large bald character can be seen to be shouting or yelling, however, there is no sound of yelling.
Revealing mistakes: In the final battle sequence, after the first wave of attack is slaughtered, the last survivor comes out of the door at the gate and collapses. Right before he does the door behind him closes. When we see the gate from the Saxon's side the door is open. Then it's closed on the Roman side and the door is open again in the next scene.
Continuity: In one scene Guinevere is seen wearing a dress that has one shoulder bare, in the next scene, the opposite shoulder is bare.
Continuity: Once when Arthur is talking to Tristan, his hair changes from being in front of his face to brushed to the side and back again to in front of his face between shots.
Anachronisms: Crossbows were not a feature of warfare in fifth century Britain.
Anachronisms: Arthur and his knights are wearing modern shoes with modern lacings.
Anachronisms: The Pope did not have the power to give land to a people. This was possible nearly 400 years later.
Anachronisms: The "traitor" outside the gate of Hadrian's Wall is seen hiding in a Horse Chestnut tree. However these were not introduced to Great Britain until the middle of the sixteenth century
Anachronisms: When Guinevere is kneeling next to Lancelot's body at the end of the battle, the modern heels of her boots are clearly visible.
Crew or equipment visible: Just after the end of the first battle with the Woads, Bors draws back the curtain of the carriage to look in on the Bishop. As he does so, the leg and boot of a crewmember is visible inside the carriage.
Continuity: When the knights are going back to the fort after the first fight, their positions in the group change between shots. After talking with Bors and Gawain, Lancelot rides forward, but in the next shot is back again.
Continuity: Despite the fact that it's supposed to be winter, there are leaves on the trees.
Miscellaneous: When Bishop Germanius enters the Great Hall he queries the number of knights present although he carried only one box of six discharge papers - the exact amount for the knights present. Although Arthur made seven, he was not included as he was a Roman Commander.
Continuity: During Arthur and Lancelot's discussion before they leave on their mission, the lighting falls on the left side of Arthur's face in close up, and the left side of Lancelot's, despite the fact they are facing each other. In the wider shot moments later, the right side of Arthur's face is illuminated (as it should have been all along).
Audio/visual unsynchronized: After they rescue Guinevere and Lucan and they're riding along the road, Lancelot goes up to Arthur and says "If the Saxons find us we will have to fight." His lips don't move along with the words.
Continuity: In the winter scenes, none of the actors have frosty breath since the scenes were actually filmed during the summer.
Continuity: The traitor who was originally killed in the tree by Tristan is later on seen in the film right after Arthur kisses Guinevere, in the center of the cheering crowd.
Anachronisms: One of the knights flies a hawk in several scenes. The hawk is a Harris' Hawk from the Americas - the Americas were not discovered until nearly 1,000 years later.
Revealing mistakes: In one scene in the last fight there is blood on Tristan's clothes, but in the scene after it is gone.
Factual errors: During the battle on the frozen lake, Tristan fires three or four arrows at once. This would cause the bow to break.
Continuity: After Arthur gets slashed in the neck during the ice battle, his neck is bandaged during Dagonet's funeral, and you can still see the blood. In the sex scene with Guinevere that night though, there is no bandage and not even a scratch on his neck.
Factual errors: In this movie, the Saxons are invading from the North; in actual historical fact, the Saxons invaded from the South, as the first Saxon Kingdoms in Britain were in Kent. Also, at the beginning, the Saxons were actually invited in to help defend against raiders from the North sea, later known as the Vikings. Further, the Battle of Baden hill did not occur until several centuries after the Roman's abandoned Britain, and Baden Hill is not just behind Hadrian's wall, but much farther South.
Anachronisms: Barbed wire did not exist at the time of this film, it was developed in the 1800s
Revealing mistakes: There was no one to open the gate in Hadrian's Wall during the Battle of Baden Hill: it just opens and closes on its own.
Revealing mistakes: Along with many other indications that the movie was not shot in winter is the fact that the snow falling on Dagonet's face does not melt on contact. Either Dagonet was inhumanly cold, or the "snow" was plastic.
Continuity: During the fight scene, where Dagonet is pulled from sleep by Marius' roman soldiers, he pulls a knife from his boot with his right hand. The next shot shows it is raised in his left hand, and the next shot has it back in his right hand.
Anachronisms: In the final battle scene, the Britons are shown using trebuchets. Catapults would have existed in Europe at this time, but they are clearly using trebuchets instead. The traction trebuchet did not reach Byzantium from China until sometime in the 6th century CE (nearly 1000 after its initial development in China), and the counterweight trebuchet did not reach Europe until the 12th century.
Factual errors: The film is set specifically in 467A.D., yet includes: the official withdrawal of the Roman army from Britain actually prior to 410, one of St. Germanus' visits to Britain in 429 or 447, Cerdic and Cynric's arrival in 495 and deaths in 534 and post-556 respectively.
Factual errors: Pelagius did not advance a theory of political freedom, but resisted the doctrine of original sin, arguing that one was able to perform good works and achieve salvation by sinlessness alone without requiring spiritual Grace. It was declared a heresy of the Roman Church in 418 A.D.
Factual errors: The concept of a knight did not come into being until about 400 years after this movie supposedly takes place.
Anachronisms: In the last battle scene, the fortress is of the 3rd middle age style, dating it about 1000 years after the movie is set.
Crew or equipment visible: During the final battle scene the camera pans all around the inside of the wall. If you watch as the camera pans the very top of the wall, where the stones are staggered, you see another camera moving on a sort of zip line as the battle rages on.
Anachronisms: The swords are from well after the setting of the movie. Roman troops would have been equipped with the spatha. The swords are a medieval design which did not appear until at least six hundred years after the time setting. The other hand weapons of the "knights" are equally incorrect.