Factual error: The movie takes place during the year 1919. Yet before one of the World Series games the stadium announcer requests that everyone stand up to sing "the national anthem". The US did not have a national anthem until the 1930's when Frankin D. Rosevelt signed into law the Star Spangled Banner as the nation anthem.
Suggested correction: According to Ken Burn's "Baseball", Burns and Ward verify that "The Star Spangled Banner" was sung at a baseball game in 1918 to support the efforts of American Troops in WWI- in which players like Ty Cobb, George Sistler, and Christy Mathewson all fought.
The mistake is saying the announcer called it the national anthem, not that they sung "The Star Spangled Banner."
Factual error: When Maya and team first enter the hangar at Area 51 to see the helicopters, mechanics are working on them with socket wrenches. However, when they use the socket wrenches, they turn them one way to make the ratchet sound, then lift the wrenches up off the bolts to put them back in their original position, and do it again. In fact, the way they are holding the wrenches with both hands indicates there might be no bolt there at all. In other words, they are doing absolutely nothing...just making a ratchet noise.
Factual error: When Lt. Lee shoots down the second Messerschmidt in Italy, you can see it is a twin engine plane.
Factual error: The kid is wearing a Texas Rangers baseball cap. The Rangers didn't come to Texas until 1972.
Factual error: Approximately three quarters of the way in to the film, there is a close up of a German soldier handing an officer a file of documents. The helmet that the soldier is wearing is a post war 1960s version. This can be determined by the lack of an air vent and rivet on the side of the helmet.
Continuity mistake: In the final shot, just as the credits are rolling, the British warships are sailing away with the sun setting behind them. In an earlier scene the radio commentator says that the sun is setting and a shot of the sun touching the surface of the sea is shown.
Visible crew/equipment: When Brad Pitt is taken prisoner by the English, he tries to escape and is thrown in prison. As the camera turns back to the door, the shadow of a microphone is visible left to the door.
Factual error: One of the members of the orchestra is reading off sheet music held together by sticky tape, which is an anachronism.
Revealing mistake: While Noro, a member of a shoeless society, is doing his uphill training you get a glimpse of his shoes, in spite of all efforts to hide his feet in the grass. (00:53:30)
Factual error: Secretary of State John Hay is depicted issuing the order to "initiate hostilities" against Spain. Unfortunately, at the time we actually went to war with Spain, John Hay was not the Secretary of State. That position was held by William. R. Day. Hay did not become SofS until September of 1898, after most hostilities had ended.
Factual error: In the scene towards the end, where Johnny Depp is making his speech in the House of Lords, he refers to 'due process of law', but uses the American pronunciation of the word 'process' (prah-sess) whereas the English would say 'proe-sess'.
Factual error: Many palace scenes in the mini-series are set in the Forbidden City. This is incorrect, as the Forbidden City was built under the Ming Dynasty (1368-1644) and not completed until about 1420, almost 100 years after Marco Polo's death.
Factual error: In an early scene, a character suggests that a man might be awarded an OBE honor if he wins the 1913 US Open. The OBE wasn't established until 1917.
Continuity mistake: During entire scene with dancing king Herod and his men, shadows on the floor are at different angles from one shot to another. (01:16:15 - 01:19:30)
Continuity mistake: The actress loads her 35mm Praktica camera with Kodak film. That's not really strange, but the film is situated in 1968 around the invasion of the Russians in Prague. The film cassette is clearly visible as having DX coding on one side for setting the film speed automatically. This feature had yet to be invented in 1968, because it was released in the early 80's.
Continuity mistake: The book Geronimo steals from the wagon train is red. When he gives it to his wife it is black.
Factual error: In the ambush-on-the-prison scene, one of the Boers is equipped with a Lee-Enfield CLLE Charger-Loading Rifle. Although the Boers used many captured Lee-Enfield and Lee-Metford rifles, the CLLE's weren't even developed until the Boer War had ended.
Factual error: The movie is supposed to be in the 15th century. In a scene we see a priest, wearing a Jesuit robe. But the Jesuit order was founded in the 16th century. So it's impossible that a priest wearing a Jesuit robe appears there.
Factual error: In order to make Polyphem drunk, Ulysses and his men produce 'wine' by treading on grapes. Only thing is: without fermenting the stuff for a few months, all you get is grape juice, which is not even remotely intoxicating.
Continuity mistake: Upset with her husband's growing obsession with his mistress Maya, Tara the Queen attempts to commit suicide by slicing her wrists while bathing. She makes deep cuts in both wrists. Maya rescues Tara the Queen when she enters the Queen's chambers. Two scenes later, Tara the Queen attends the execution of Maya's lover. Magically, Tara's arms are unbandaged and unscarred. The execution took place only days after her attempted suicide.