Fictional history often betrays itself with what are called ‘anachronisms’. This is when an object, person or event is attributed to the wrong period. They can be rather glaring and undermine credibility in the whole story.
Some anachronisms are humorous mistakes. Fans of archaeology might note the maps that appear in Raiders of the Lost Ark showing Indiana Jones’ plane flying over Thailand and Jordan in 1936 (see photo). Those countries did not exist, or at least had no such names, until some years later. In the 1959 film Ben Hur one of the chariot racing Roman soldiers is wearing a wristwatch. In the 2004 Troy movie, coins are placed on the eyes of corpses, problematic as it is set centuries before the invention of coins.
Anachronisms in historical stories can simply reflect the time in which they were written and do not necessarily undermine the credibility of the story they tell. In fact, most of us have probably retold Biblical stories to children using little anachronisms to help our listeners engage. David packed his lunch in a tupperware box or Jonah put his sunglasses on. Such flavour is inaccurate but probably harmless and tells us more about the time in which the story is being retold.