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: 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.

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.

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.

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.

Factual error: In the beginning, which is around 400 A.D., it shows that the saddles have stirrups on them. Stirrups were not introduced in Europe until centuries after the fall of the Western Roman Empire.

Factual error: Tristan's bird of prey is a Harris Hawk - a species native to Southern America and thus unknown and unavailable in Europe at the time the movie is supposed to take place.

Factual error: The Saxons are seen invading to the north of Hadrian's' wall. In reality, they invaded to the south of it, and that is the reason why they managed to take control of Southern England.

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.

Visible crew/equipment: When Arthur is riding with his knights in the open field, there's a front shot of the cavalry line. When the camera lowers down to where we can see the legs of the horses, the trail of the camera stage is visible on the ground.

Revealing: In the shot where Guinevere and Arthur are kneeling over the slain Lancelot after the battle with the Saxons, you can see molded rubber soles on Guinevere's shoes.

Audio problem: When Arthur is telling the knights about their final mission, just after Bors storms out, he says, "Venora'll kill me.", but his lips don't move.

Revealing: When Lucan draws the ring of dead Dagonet's finger, you can see the finger move and keep its position.

Continuity: The knights reach the outpost beyond the wall. One of the knights reports to Arthur that the Saxons are approaching. During the exchange he's shown with his hair pushed off his face, then its covering one side of his face, then its off again.

Factual error: The scene in which the two armies confront each other on the frozen lake contains several flaws. First, when thick ice is broken with a sharp object like a pickaxe, you merely get a hole through the ice, it will only fragment into large pieces if it is thin. Clearly, this is not the case, as the armies are able to walk on it. Second, ice does not shatter in the way depicted in the film, with cracks travelling outwards a great distance, but just crumbles around the area where force is applied. Third, if cracks did radiate outwards, they would propagate sideways and backwards as well as forwards (like glass does when it is punctured by a small, sharp object), meaning that both armies would end up falling through the ice.

Factual error: Two things are wrong about the trebuchets. While Romans did have siege engines, like the catapult and the ballista, the trenches apparently is a Chinese invention. In any case, it wasn't introduced in Europe until the Middle Ages. Also a trebuchet is a complicated device, much more difficult to operate then it looks. Firing it is easy, but hitting a target certainly isn't. (With modern reconstructions, even when using ballistic calculations, it still takes days of practice to get to a point of some accuracy.) When the Roman army left, the trebuchets were completely useless. In the final battle the Woads nevertheless use them to great effect - impossible.

Factual error: Arthur and his men are charged with passing Hadrian's wall and taking the Roman family to safety; yet at that time in history there is no way a Roman family would be in Scotland; they certainly wouldn't have had a castle (no matter how small) and a peasant settlement. Missionaries or not, the Scots would have driven them out.

Factual error: The major Saxon invasion (the one we see in the movie) was set around 400 A.D. After a short time in the film, the battle of Badon Hill starts. This battle occurred in 512 A.D. Arthur must be VERY old.

Revealing: At the start of the film when the Bishops convoy is ambushed by the Woads Arthur stabs his sword at the ambusher, totally missing but the Woad still falls as if stabbed.