Alexander (2004) - 6 mistakes

Revealing: Towards the beginning of the movie, young Alexander tames a horse and then jumps on the horse and rides off. He is supposed to be riding bareback, but in one of the shots from a distance, you can tell that the actor's feet are in stirrups.

Deliberate "mistake": When Alexander is giving his pre-battle speech at Gaugamela, some of the shots are 'flipped', which has the odd effect of suddenly making all of the phalanx pikemen left-handed.

Factual error: The backdrop to the party scene in India shows a large building with glass windows. The Romans were the first to use glass windows some 300 years later.

Factual error: Just before old Ptolemy starts telling his story of Alexander, at the very beginning of the movie, we see a shot of the famous Lighthouse of Alexandria. It's fully operational, which is a mistake because the building was finished during the reign of Ptolemy's son, Ptolemy II Philadelphos, some years after the first Ptolemy's death.

Factual error: Contrary to what's depicted in the movie, Cleitus was never involved in the murder of Parmenion. He was in fact on his way to Alexander when Parmenion was killed.

Continuity: Towards the beginning of the movie, young Alexander is receiving a wrestling lesson and his hair is extremely blonde. A short time later, young Alexander is outside with his teacher and fellow students and his hair is more brownish-blonde.