Here is some trivia I found on the IMDB and other internet sources:
The Adventures of Robin Hood (1938)
This film was a truly international production. It featured an Australian (Flynn) a Hungarian director (Michael Curtiz), an English star (Basil Rathbone). The score was by a Czech (Erich Wolfgang Korngold); the art direction was by a German (Carl Jules Weyl) And the photography by an Italian (Sol Polito).
The film plays very fancifully with real history. Even the opening titles are full of inaccuracies.
Despite his flamboyant performance as Robin Hood, Errol Flynn privately professed that he found the role a boring one.
Although shot on location in California, indigenous English plants were added and the grass was painted to give a greener, more English look.
At 28, Errol Flynn was the youngest actor to play Robin Hood.
Prince John could not write out a warrant for Robin Hood’s arrest because he was illiterate; he “signed” the Magna Carta by putting his seal on it. And the Duke turned King Richard over to his own ruler, and it was this king who asked for the ransom on Richard’s life, not the Duke.
All the sword fighting scenes show the characters using one-handed swords. At this time, swords were two-handed swords, the necessary refinements in steel making that allowed lighter, more maneuverable swords had not been developed.
Walt Disney’s Robin Hood (1973)
Originally, Friar Tuck was to be a pig, but was changed to a badger to avoid insulting religious sensibilities.
Robin Hood: Prince of Thieves (1991)
Kevin Costner had originally hired a coach to help him learn to speak English with an “English” accent. He had too much trouble learning it though, fired the coach, and decided not to do it.
At the wedding, Tuck says “I now pronounce you husband and wife”. “Husband” wasn’t used until very late in the 20th century.
The Sheriff uses the word ‘thugs’ although this word isn’t commonly used until the British Imperial rule in India some 500 years later.
Robin and Marian (1976)
Golden Delicious apples (in windows during last scene) did not exist in 13th century England.
Robin Hood 2010
The production had planned to recreate the Tower of London in Caernarfon, North Wales but later decided on doing the tower digitally.
At 45 Russell Crowe is the oldest actor to have played Robin Hood in a movie. Sean Connery was nearly 45 when he played a veteran Robin Hood in Robin and Marian (1976).
Eileen Atkins replaced Vanessa Redgrave, who dropped out, after the accidental death of her daughter Natasha Richardson.
During an interview with Mark Lawson Crowe stormed out when Lawson accused him of having giving the hero an Irish accent.
Mark Lawson: The accent that you’ve given him, there are hints to me of Irish, but what… were you thinking in those terms?
Russell Crowe: ‘You’ve got dead ears mate, you’ve seriously got dead ears, if you think that’s an Irish accent.’
Lawson: ‘Hints of, I thought…’
Crowe (interrupting): ‘B*******.’ (Crowe then talks about his portrayal of Robin Hood before coming back to the accent issue)
Crowe: ‘I’m a little dumbfounded you could possibly find any Irish in that character, that’s kind of ridiculous anyway, but it’s your show.’
Lawson: ‘So you’re… well, I am just asking… so you’re going for northern English?’
Crowe: ‘No, I was going for an Italian, yeah, missed it? (Laughs) F*** me!
(The actor then refuses to answer a question about whether he had not wanted to deliver some of his most famous lines in Gladiator)
Crowe: ‘I don’t get the Irish thing by the way. I don’t get it at all.’
(He finishes the interview, waving his cigarette and walking out).