Robbing the rich to give to the poor arrives very late
The oldest surviving ballads are from the 1400s, and in them ROBIN is a violent yeoman who robs people on the road, beheads the SHERIFF and puts his head on a stick. He is generous to those who treat him decently and murderous to those who do not, but the idea of a systematic redistribution programme is simply not there.
The famous phrase attaches to him around the 1500s and hardens later. The other large change happens at the same time: he becomes a dispossessed nobleman, the Earl of Huntingdon, robbed of his lands. That is a very different story — a wronged aristocrat reclaiming his rights is a much safer hero than a commoner who kills officials, and it is the version that got written down by people with something to lose.
There is no original Robin Hood
Historians have looked hard. Court records from the 1200s onwards contain men called Robinhood, Rabunhod and similar, but the name appears to have become a generic label for an outlaw — a fugitive would be recorded under it the way a modern report might say an unknown man. Several of them cannot possibly be the same person.
So the search runs backwards: the stories are probably not about a real man who was then exaggerated, but a legend that real criminals were filed under. The forest is more consistent than the man. GREENWOOD outlawry was a genuine feature of medieval England, where the king's woods carried their own brutal laws and a man who fell foul of them could vanish into the trees and live outside the reach of a CASTLE.
Half the cast joined later
LITTLEJOHN and Much the Miller's son are in the earliest ballads. FRIAR TUCK turns up in the 1400s, borrowed from a separate outlaw tradition. MARIAN comes from French May Day games and is grafted on in the 1500s, leaving her feeling like a guest in her own story. Will Scarlet drifts in and out.
Even the archery is an addition of emphasis rather than an invention. Robin uses a BOW in the old ballads, but so does everyone; the longbow was the ordinary weapon of the English yeoman, and the ARCHER with his QUIVER splitting an ARROW at a tournament is a set piece that grew because it is a good scene. Each century adds what it wants and the character absorbs it.
Why he will not go away
Almost every generation has needed a version. He has been a Saxon resisting Normans, a Jacobite, a socialist, an environmentalist and a freedom fighter, depending on who was telling it. The reason the frame survives is that JUSTICE and the law are not the same thing, and a story about an OUTLAW who is morally right is available to anybody who feels the rules are rigged.
The rest of the grid is the furniture that every version keeps: SHERWOOD and the MERRY men, DISGUISE as the standard tactic, the SHERIFF of NOTTINGHAM as a figure of local corruption rather than national tyranny, and the willingness to STEAL from a BANDIT's point of view. Strip out the hat and the tights and the machinery underneath is still perfectly serviceable.