Factual error: On the cliff top before the battle on the beach, you are treated to a lovely if fleeting glimpse of wind farm turbines, not really fitting for the 12th Century.
Factual error: In the beginning of the film, the opening text states that it is the turn of the 12th century. However, the first scene of the movie says that the year is 1199 A.D., which is the turn of the 13th century.
Factual error: Richard I was not fighting his way back across Europe following the Crusades when he was killed. He had already returned to England and put down John's rebellion before returning to France to put down rebellions there.
Factual error: The Viking style funeral that Robin's adopted father has would have been unthinkable at the time. Cremation wasn't just against the law, it was completely against the teachings of the Church. He would have been interred in the family crypt or, if that had been destroyed, buried.
Factual error: Richard, John and Eleanor are all addressed as "Your Majesty." Henry VIII was the first English king to use that form of address, in the 16th century. Medieval kings and queens were addressed as "Your Grace."
Factual error: Isabella of Angoulême, (whom John is seen with during their introduction in the film) is portrayed as being in her early twenties when in actuality, she was born in 1188 and would be only 11 years old during the events of the film.
Factual error: Nottingham was an important fortified city with a castle in the Middle Ages, not a small village as depicted.
Factual error: The French invade the lands of England by crossing the English Channel. The kings of England considered Normandy, Gasconie and Aquitane to be their primary lands up to defeats in the Hundred Years War, about 230 years after the movie takes place. French invasion of England would be illogical and impractical, if not downright suicidal. Not surprisingly, English holdings in France aren't mentioned as a target.
Factual error: The invasion was supposed to be at Dymchurch, as mentioned in the Blue Ray director's cut version. In the film, the invasion area is a sandy beach flanked by cliffs. In reality Dymchurch is a pebble beach and is on the edge of the Romney Marsh with no cliffs. The lack of cliffs can be checked via OS Maps of the area.
Answer: By "Wind-up lute", I assume you mean the hurdy-gurdy. Certainly, instruments fitting the description of the hurdy-gurdy were around in the time when Robin Hood was set.
Madstunts