The film opens in the middle of the night as the Sherwood robbers run through the forest. The robbers run through Nottingham and put their horses into a stable. Lady Marion (Cate Blanchett
), wife of Sir Robert Loxley, rouses her servants and demands that they open the gates. Taking an arrow and setting it aflame, she shoots it at the feet of one of the robbers and tells them that she can see them. After they leave, she realizes that the seeds and grain of Nottingham were stolen and that they won't have anything to plant come spring.
Robin Longstride (Russell Crowe
) leads his men through the forest back to their own camp. When he fought in the Crusades, Robin was only an archer. As English troops lead an assault on a French stronghold, Robin and his men fight valiantly alongside King Richard the Lionheart (Danny Huston
). A young archer attempts to plant a bomb bag on the portcullis but gets stuck. Robin races to him and rescues him before the French can kill him. Robin then retreats to safety before igniting the gate. The English troops attack the breach.
Back in England, Richard's younger brother, Prince John (Oscar Isaac
), is cheating on his wife Isabel (Jessica Raine
) with Isabella (Léa Seydoux
), the niece of the French king. John's mother Eleanor of Aquitaine (Eileen Atkins
) walks in, passing his wife, who is standing sadly outside the room. John asks his mother to leave but she tells him that his behavior has given the king of France the excuse he needs to invade. She tells him to go to his wife, but he responds that his wife is barren. John expresses his desire to divorce his wife and marry the French girl since he anticipates becoming king upon Richard's death.
Robin sets up a memory game where he hides a pea under three cups. Most people fall for it, but Little John (Kevin Durand
) is determined to beat the game. When Robin offers three choices, Little John accuses him of hiding the pea in his hand while turning all of the cups. However, removing all three cups reveals that the pea was in the center cup all the time. Little John attacks Robin and they fight it out until they're interrupted by the king's arrival. When the king asks who started the fight, Robin says that it was his fault. The king talks to Robin and asks if he is honest enough to tell him his thoughts on the Crusade. The king wonders whether God would be pleased; Robin says no. The slaughter of the Muslims in their last battle made Robin feel that God did not approve of their actions and that they had acted like barbarians. Robin and his men are put in the stocks and Robin swears that he is done fighting and will return home once released.
In nearby woods, Sir Godfrey (Mark Strong
) visits King Philip (Jonathan Zaccaï
) of France. Philip notes that Sir Godfrey is of French and English heritage and asks where his allegiance lies. Godfrey pledges his allegiance to King Philip and Philip requests that Godfrey kill King Richard the Lionheart so that Philip may attack England under the leadership of the inept John. Sir Godfrey agrees.
Meanwhile, King Richard leads his men in battle with the French. Upon breaching the perimeter, an archer shoots King Richard through the neck. As he dies, his men call for a doctor but can only comfort his passing with wine. His knights gather the crown and prepare to depart for the boats back to England. The young man Robin saved sees the incident and runs back to the stocks to free Robin and his friends. They grab their equipment and flee the camp as quickly as possible.
Sir Robert Loxley (Douglas Hodge
) is leading the knights of King Richard through the forest when Sir Godfrey's men attack and kill most of the knights. Loxley is skewered by a spear and left to die slowly. Godfrey asks about King Richard and is surprised to hear that the king was killed in battle. Loxley tells them that the king's crown is in a bag on the king's horse. Godfrey's men attempt to recover it but the horse runs away, directly toward Robin and his men. One of Godfrey's men pursues the horse and kills the young man Robin rescued, but Robin and Little John kill him quickly and then attack Godfrey's party with their other friends. Godfrey and his men retreat before they can loot the corpses. As Godfrey runs off, Robin shoots him in the cheek with an arrow, scarring him.
Robin finds Loxley dying. Loxley tells him that he stole his sword from his father and his dying wish is that it be returned. He reflects on the love a father and son share and dies. Robin vows to honor the promise. They loot the corpses, don the armor and pretend to be knights. Robin explains that the disguise will allow them to obtain passage back to England as the crown's honor guard. They bury their dead comrade and leave for the shore.
In Nottingham, Lady Marion visits the church to meet the new friar, Tuck (Mark Addy
), and ask for seed to help the people. The old friar, departing for York, tells her that the church will not be surrendering its grain. Lady Marion is outraged that the church will not practice charity for its people. The departing priest tells Tuck that the Loxley family is always causing troubles for the church.
Robin and his men arrive at the ships and present themselves as knights. The guardians of the ship tell Robin that they were expecting 12 knights and the king but Robin informs them that Richard is dead and presents them with his crown. They bring the men aboard and set sail for England. The men drink and sing but Robin examines the sword of Loxley. He unwinds pieces of metal and sees that the inscribed motto reads "Until Lambs Become Lions." Little John asks the plan and Robin explains that they will go north from London after delivering the crown.
The next morning Robin wakes up and sees they are 40 minutes away from England. His men are scared that their masquerade will be undone by the members of the royal court. Robin tells his men that they should be ready to run for their lives if they are recognized as impostors. The royal court expects to see the king disembark. However, King Richard's mother Eleanor suspects something is wrong when Robin comes ashore instead of Richard. Robin gives the crown to Eleanor.
Sir Godfrey watches from afar as Robin delivers the crown. For a moment they are concerned that Loxley lied about the king's death. Prince John is shocked that his brother is dead. His mother places the crown on John's head, as he is now king of England. Robin presents himself as Loxley of Nottingham and John asks how his brother died. John offers Robin a reward. He asks if Robin said he was from Nottingham. Robin hesitantly says yes and John says that Sir Walter Loxley (Robert's father) owes taxes to the crown. John offers Robin his ring but then takes it back, saying that is his first payment. King John greets Sir Godfrey and invites him to dine with him later.
William Marshall (William Hurt
), a man in the crowd, tells Robin that he will visit Sir Walter soon. Robin says that he will deliver the message. Godfrey knows that Robin is impersonating Loxley and tells his men that since he knows too much, he must be killed. Robin rides out of the city with his men toward Nottingham.
Lady Marion and her servants are plowing a field when the sheriff arrives and tells her that he expects an audience with Sir Walter. Lady Marion asks why he isn't taking care of the robbers in Sherwood instead. The sheriff says Sir Walter needs to pay his taxes and the sheriff will come and break down the door to collect the money. He makes an advance on Marion, who threatens that her husband will kill him, but the sheriff laughs at her. He tells her that her husband is surely dead after ten years and leaves her alone in the field.
The men eat and sing together in the forest until Robin abruptly suggests that they part ways after dividing the spoils. Little John asks where Robin will go. Robin tells them that he has to honor the dying wish of Loxley. His men call him crazy but Robin tells them that he owes it to Lady Fortune.
King John and William Marshall discuss the financial cost of the army of England. King John wants to disband but Marshall points out that it would be more efficient just to keep it together. The war has ravaged the economy and the people are feeling the strain.
Marshall tells him that he should take out loans from Normandy but John just wants to tax the people. Godfrey presents himself and offers to collect the money or kill those who refuse. Marshall is taken aback by this but Godfrey tells him it's what must be done. King John thinks this is well said.
Eleanor, the queen mother, tells John that Richard would have done things differently. John loses his temper with her and blames her for the wreckage of England. She slaps him and leaves the room. King John forces Marshall to resign and dismisses him from court. Godfrey follows him out and Marshall tells him to choose the spot where he places his dagger carefully. Godfrey mocks him by showing him the seal that grants him Marshall's position and leaves.
Robin and his men arrive in Nottingham. They are unimpressed by the setting. Friar Tuck, who takes care of the bees, addresses them. He tells Robin where to find the house of Loxley, and Robin rides off. The others ask where they can find liquor but Little John apologizes. Friar Tuck exhorts them and offers them some honey liquor (mead).
Robin arrives at the Loxley house. He sees Lady Marion milking a cow and addresses her rudely as "girl" while checking her out. He introduces himself as Robin Longstride and asks to see Sir Walter. He tells her that Robert is dead and she leads him inside. She says that she is Robert's wife. He tells her how Robert died. She advises him to lie to Sir Walter about Robert's death. Sir Walter (Max von Sydow
) is blind but Robin gives him his sword back. Walter knows his son is dead when he feels the sword; he asks what happened. Robin tells him that Robert's final words were of his love for his father. Walter guides his hands over Robin's face. He asks Robin to dinner and tells him that he needs to bathe first.
Lady Marion offers him her husband's clothes. He asks for help taking off the armor he is wearing. She is uneasy about this but complies with his request.
Walter asks Robin about his journey. Robin tells Walter his life story: He was abandoned as a child and doesn't know his origins, only where he's been. Walter makes an offer: if Robin gives him some time, the sword of Loxley will be his. Walter says that he can tell him something of his history. He goes on to request that Robin stay and pretend to be Robert so that Marion can keep her land. Walter says that Robin must become his son. Robin agrees, despite Lady Marion's rage.
The House of Loxley celebrates the "return" of Robin. Robin's men are impressed by the women. Friar Tuck asks why they call him "Little" John and John replies by telling him that he's got a proportionate penis before pursuing some of the women at the party.
Lady Marion and Robin must share a bedroom to maintain the ruse. She asks if he is coming to bed, but he tells her to ask nicely. She sarcastically requests that he return to their room. Robin reflects on the sword's motto by the fire before retiring to the room. They share the room but Lady Marion tells him that if he touches her in her bed, she will stab him. Robin lies by the fire with a lamb and goes to sleep.
Godfrey meets with his French counterparts in a dark field. They are ready to launch their attack on England and on King John. Marshall receives a note meant for Godfrey which warns that 200 French soldiers have landed in Britain.
Sir Walter greets Robin in the morning. He calls Lady Marion and tells her to show Robin around Nottingham in order to familiarize him with the village and its people. Lady Marion shows him around the fields despite her misgivings. He asks where the cows and sheep are. She replies they are gone, and that all they eat are rabbits and pigs. She mentions that the deer are off limits since they all belong to the king. She tells him to act like Sir Robert. Villagers greet him and he pretends to know them. Lady Marion is introduced to Robin's companions in arms. He tells them to pretend he is Loxley and they agree, but mock him as well.
Friar Tuck meets with Robin and Marion. Marion tells Tuck that they are stealing grain that the people of Nottingham had raised under the guise of tax. Robin asks if the church knows that Tuck is raising bees that produce honey. Tuck responds by asking, what if the grain doesn't reach York? Robin tells him that the church won't need to know of the bees.
That night, Robin pays a visit to Friar Tuck. They drink mead together and Robin tells Tuck that they need to steal the grain for Nottingham. Pretending to be the Sherwood robbers, they steal the grain. They take the grain and plant it in the fields during the night as it starts to rain. Lady Marion is impressed by Robin's actions and sees him sleeping near the fields. She asks how he found the seed, but he doesn't tell her.
Godfrey leads his men in the name of the king to the towns which refuse to pay their taxes. Godfrey and his men slaughter the townspeople in retaliation. He takes the gold by force and leaves entire towns aflame.
Marshall visits Queen Eleanor and tells her he has lost faith in John. He tells her that Godfrey is pissing off the Northern barons to provoke them to attack the throne so that England will be in chaos when the French invade. Eleanor tells John's new wife, Isabella, that a paid agent of France is planning an attack. She tells Isabella that if she wants to earn the title of queen she must tell John that Godfrey is plotting against him. John flips out when he hears this. Isabella tells him that it's true and that if he doesn't believe her he should kill her. He kisses her and begs her forgiveness.
A messenger demands an audience with the sheriff of Nottingham and delivers a letter telling him that Godfrey is coming to Nottingham. He tells the messenger that Loxley will be trouble.
Lady Marion describes her married life. The daughter of a widow, she was married a week before Robert left for war. Robin tells her that Robert was a good knight. He helps her mount her horse and they ride off.
King John visits Marshall and asks why he deserted him when Godfrey is planning to help the French attach him. Marshall tells him that they need to reach out to the Barons of the North and that King John must meet them. King John tells him that they will be taking the militia to meet with the barons in battle. Marshall requests a horse from his servants so that he might find the Northern Barons.
The messenger returns to Godfrey and tells him that he found Robin. Godfrey tells him that when they arrive in Nottingham they will take no prisoners and will make the place famous from how much blood will be shed.
At a village dance, Robin dances with Lady Marion in front of everyone. Afterward, Walter tells Robin that his father was a visionary and a philosopher. "Until Lambs Become Lions" was his motto and he was able to galvanize the people with his words. Walter tells Robin that when Robin was younger he witnessed his father's execution. Robin bursts into tears when he realizes the truth. His father had written a charter of rights and Walter shows it to Robin. A messenger arrives from Marshall requesting Sir Walter's assistance in preparing the troops.
Robin rides out to Marshall, who is telling the barons of the North that Godfrey is attempting to cause chaos so that England can be conquered by France. King John arrives and takes the stand. King John claims that Godfrey was acting only to cause chaos and his men point out that he did so easily. Meanwhile, Robin arrives at a burnt down town and sees the ground where his father was killed years before. He strikes a stone on a statue and removes it to find a hand print he left as a child. He walks over to Marshall as King John speaks. He announces his arrival and tells his people that their tyranny is the heart of failure. He asserts that every man deserves power and that King John's demands will be his undoing. Robin incites the crowd with his words and tells King John that liberty by law is the right of all men. They gather and prepare for war.
Godfrey leads his men to Nottingham and prepares to slaughter the townsfolk. The men march to Sir Walter's house looking to kill Robin. Walter walks out, blind and carrying his sword. Godfrey tells Walter that he killed Robert. Godfrey toys with Walter but Walter succeeds in cutting Godfrey's face before he is run through and killed. Godfrey's men collect the money of the town. The Sherwood robbers see what is going on in Nottingham. Friar Tuck manages to trap a few soldiers in the bee house and leaves them to die. The messenger attempts to rape Lady Marion. She goads him before stabbing him in the neck and killing him.
The Sherwood robbers help Marion escape as Robin arrives and leads the attack on Godfrey's men. Godfrey retreats with what men survive to meet up with the French in the south. Walter's servants bring the sword of Loxley to Marion, telling her that he is dead. She gives him the sword and Robin hugs her. They burn Walter's body on a funeral pyre. Robin tells Marion he will come back. They share a kiss and he tells her that he loves her.
The French begin their invasion of England as Robin and his men ride for the coast preparing for battle. King John asks Robin and Marshall what they need to do to beat the French. Robin leads the archers to the cliff tops as Marshall leads the ground troops. They charge the French in battle. Little John brutalizes the French troops along side Robin's other men. King John charges into the fray for personal glory. Lady Marion, dressed as a man, attempts to kill Godfrey but he drags her into the water and attempts to drown her. Robin charges Godfrey and tackles him. The two duel on the shore in front of the French boats. Marion forces herself up while Robin is caught between two French boats. Godfrey flees. Robin escapes from the boats and picks up an arrow. He sees Godfrey in the distance and shoots him through the neck. Robin then pulls the unconscious Marion out of the water and kisses her. The English troops push the French back and King Philip orders a retreat. The English are victorious. King John sees Robin carrying Lady Marion away.
King John perceives the French as surrendering to Robin. Seeing him as a threat, he declares Robin an enemy of the crown and an outlaw. He refuses to sign the Magna Carta presented by the people. He silences his people and burns the document.
The sheriff of Nottingham reads a declaration that anyone who helps Robin will be killed. In lieu of a nail, Robin shoots the order into a wall as an act of rebellion. Marion, Robin, and his men retreat to Sherwood Forest.