Every fairy-tale needs a forest. The forests of northern Europe were the crucible of folk imagination, magical, confusing, a tangle of dangerous dark sexuality (see the thorns around Sleeping Beauty), where you stray off the path (like the Babes in the Wood or Red Riding Hood); where (like Snow White) you meet figures you never encounter elsewhere. Britain had all that too, but by the thirteenth century had its own extra take on the legendary forest. The Norman kings imposed a law which made all forests the king's "secret place", whose animals were ferociously protected for him alone to kill. This, plus post-Conquest Saxon-Norman conflict, is the background to the Robin Hood legend.

The films faithfully reflect all that. Robin is a Saxon lordling (as in Walter Scott's Ivanhoe): Kevin Costner or Patrick Bergin standing up on forest land he thinks of as his, to champion a peasant caught poaching deer against a foul Norman baron enforcing the king's law. Then, outlawed, Robin sets up court in the forest. This is the peculiar British spin on fairytale forest (reflected in As You Like It and A Midsummer Night's Dream, as the forest of Arden or Oberon's fairies): the alternative woodland court, a fairer society at the heart of the king's secret domain. In T.H. White's Sword in the Stone, Robin is not Hood but Wood. "What else should un be," says Little John, "seeing as he rules 'em?"

As the wood's guerilla "ruler", Robin exists between the king's justice and injustice. His earliest screen appearance (in a British film Robin Hood and his Merry Men, 1909), lined him up, like most films since, with Richard Lionheart (absent on crusade) against the wicked Regent Prince John, to a backdrop of brutal taxes and tortured peasants.

How true is all that? If Robin lived, it was in the twelfth or early thirteenth century, for he figures in songs and chronicles of the late thirteenth and fourteenth centuries. A portion of the Pipe Roll of 1230, relating to Yorkshire, mentions a "Robertus Hood fugitivus". Other traditions say he was born 1160; or (it was a common medieval name) is in prison in 1354, awaiting trial for offences commited in Northamptonshire woodland. He died 18th November 1247 - or in 1325. Or he was Robert Fitzooth, Earl of Huntingdon, from Locksley, Nottinghamshire, who fled to the woods in disguise. Or Robin and Little John were defeated with Simon de Montfort at the battle of Evesham. Or Robin is yeoman stock; hence his woodcraft. He turns up in Barnsdale in Yorkshire; in Nottinghamshire, in Plumpton Park in Cumberland, or Sherwood Forest.

But whoever, whenever, wherever, behind his woodland existence is a politics of disaffection which made him the folk hero of over eighty fourteenth-century ballads, the "Rymes of Robyn Hood". They are full of James Bondish fights, adventures, and escapes, but also that longing for a people's hero who plunders the rich to give to the poor. And they emerge around the time of the Peasant's Revolt (1381). Robin is against nobles, the law (the Sheriff of Nottingham), fat corrupt churchmen, and feudal injustice. He is a matchless archer: generous, brave, imaginative; a mediaeval Batman or Scarlet Pimpernel.

And also monumentally chivalrous:

I never hurt woman in all my life
Nor man in woman's company.

Womankind responds by killing him. He is bled to death by a treacherous nun suborned by his cousin, prior of Kirkless in Nottinghamshire. But his men - Allen-a-Dale, Will Scarlet, Little John, Friar Tuck - though they often start as antagonists (the fight on the bridge, the challenge in the cart), end by adding their own special qualities to his band. Hollywood (Douglas Fairbanks in 1922, Errol Flynn in 1938), fell on Robin as the fore-runner of the cowboy outlaw with different talents (like The Magnificent Seven) in his support team.

Yet Robin came from deep in the British countryside and its idioms. There were country sayings like "go round Robin Hood's barn" (get to the right conclusion the long way round), "sell Robin Hood's pennyworth" (sell half price), "Robin Hood's feather" (a hatband), "Robin Hood's bargain" (a pennyworth). Hundreds of hills, plants (especially flowers) and trees throughout England and Scotland bore his name. For he also flickers out from a far earthier layer of folk imagination and life. From very early on, Robin Hood was also "King of the May". By the fifteenth century, he is the hero of many folk plays which were assimilated to Morris Men's danced stories, and the May Day pageants in which Maid Marian was also a character. (In later tradition, she gets drawn into his exploits because she was Columbine to his Harlequin in dances and May Day partying.) Behind Robin Hood are the springtime rites of village sex, pushed out of sight to the greenwood. The night before May Day you spent with lovers in the woods. As Amiens sings, in As You Like It, Under the greenwood tree Who loves to lie with me...? When Theseus (about to get married himself) sees the lovers of A Midsummer Night's Dream asleep in the forest, he guesses that "they rose up early to observe/The rite of May".

Fpr Robin (the only "merry" man in that wood who has a woman) is lord of spring lust and lustiness. The "Lincoln Green" clothes were not just camouflage. Giving "a green gown" for May Day spelt sex, as in Herrick's poem "Corinna's Going A-Maying":

Then she became a silken plaid
And stretched upon a bed,
And he became a green covering
And gained her maidenhead.

Fiinally, green is fairytale's favourite colour for magic too: as in the Green Knight (from a "Green Chapel" in the forest) who disturbs King Arthur's midwinter revels). Robin Hood in green is also the "spirit of the wood": a wood demon, the Jack-in-the Green or "Green Man" whose leaf-ringed face glimmers at you on carved cloister bosses in the village church. So his woodland powers are over-determined. They come from every aspect of mediaeval British village life - ballads, politics, magic and sex. He is a hero-figure created by nearly ten centuries of British folksong, fairytale, dances, and village theatre. Plus, of course, that achingly British longing for "the greenwood".