Factual errors: As with most historical biopics, some of the events did not occur exactly as they are portrayed in the film, or may have happened at a different time. Some did not take place at all and are included purely for dramatic purposes.
Revealing mistakes: In a scene in which Elizabeth is speaking with another character with a fireplace in the background, blue gas flames are visible at the bottom of the fire, notably in the bottom right corner of it.
Errors in geography: Before each scene in Fotheringay, where Mary Queen of Scots is imprisoned, they show the castle surrounded by the majestic mountains of Scotland, the tops covered in snow. Fotheringay is actually in Northamptonshire, one of the flattest counties in England.
Errors in geography: Queen Elizabeth stands watching the Armada burning from a clifftop near her camp, which has been stated to be at Tilbury. But Tilbury is in the Thames Estuary, far from where the action seems to be taking place, and is a long way from anywhere with the kind of dramatic jagged rocks Elizabeth is seen standing on.
Anachronisms: In the film, Elizabeth's potential suitors included Tsar Ivan IV the Terrible and Eric XIV of Sweden. Both monarchs were already deceased (Ivan in 1584, Eric in 1577) at the time the film was set (1585). And even if Ivan were still alive, at that period it would have been very unlikely that an Orthodox ruler would marry a Protestant queen.
Continuity: At Mary's execution, her crucifix is dangling to the screen's left, in the next shot it is dangling in the middle.
Factual errors: The execution of Mary Stuart (Mary, Queen of Scots) is shown with a single, swift ax stroke. Historically, it was far worse, actually taking at least two strokes - the first hitting Mary in the back of the head (reportedly prompting her to cry out, "Sweet Jesus") and the second severing all of her neck save some sinew, which the executioner then cut through by using the ax as a saw. Some reports say the execution in fact required a third stroke as well.