King Arthur (2004) - 8 major mistakes

Factual error: I normally wouldn't bother with this sort of nitpicking, but this film specifically claims to be historically researched - and it's full of historical blunders. For a start, the film is set as the Empire withdraws its last troops from Britain - which was in 407 AD. Now Artorius Castus was a real Roman officer who really did command Sarmatian foederati at Hadrian's Wall, but he died around 200 AD. Cerdic was a real Saxon warlord who did go raiding the Britons with his son Cynric, but he did this in the early 500s. Pelagius really was tried for heresy, but he was acquitted and died of old age; the trial was a decade after this setting, and in the fifth century you couldn't be executed for heresy anyway. Also in the fifth century the Pope had no authority over Imperial troops. I could go on and on but that will do for now.

Revealing: When Arthur is giving his speech before the last battle, in the background are three radio towers. You never know Arthur might need a radio to find out tomorrow's weather.

Continuity: In the scene where the knights are sitting at the round table near the beginning of the movie one of the knights has a plus sign shaped scar on his forehead. In the next shot,the same knight now has a sideways cross shaped scar. The scar changes almost every shot throughout the scene.

Plot hole: When the two Legionnaires open the gate of the Hadrian's Wall, they lean forward with their shoulders against the doors as if to push, but they are really pulling.

Deliberate "mistake": When the horses shy to get their masters back to Arthur's aid you can see Bors pull the reins to provoke that action.

Revealing: At the beginning, when the Woads are attacking the Bishop's Carriage, Lancelot is hitting one of the Woads. The sword isn't even touching the Woad.

Continuity: When we see Tristan's bird for the first time, the shots changes between close up and distance. In the distance shot you see both of Tristan's arms out in the air, but in the close ups both before and after, it's only one arm out in the air.

Continuity: During the battle at the end of the movie, the first wave of Saxon infantry is sent through the open door in Hadrian's Wall, and then it closes behind them. Mayhem ensues. All but one of the soldiers escapes after the Wodes fire arrows at them while the Knights ride them down. The single survivor staggers through the opening doors (which open just a crack, enough for the guy to slip through), and then stands there, and in that shot we see the doors behind him are now closed. An instant later, it cuts to the hillside where the Knights are standing on their horses looking down at the wall, and we see the doors both standing wide open. Scene cuts back, and we see they're closed again.