NOTE: This spoiler was sent in by Renee who says..."There were a lot of historical inaccuracies, but it was still a well-made, interesting movie with strong performances."
We start with three children playing in a field, two girls and a boy. They are the children of Sir Thomas Boleyn (Mark Rylance) and his wife Elizabeth (Kristin Scott Thomas). While watching the children play, Thomas tells his wife that a merchant named Carey wants their daughter Anne to be betrothed to his son William, but Thomas plans to offer him Mary instead. Thomas favors Anne and thinks she can do better.
Fast-forward a number of years. Mary (Scarlett Johanssen) is marrying William Carey. Anne (Natalie Portman) obviously feels somewhat uncomfortable that her younger sister is getting married first (she mockingly calls herself "the other Boleyn girl"), but she is clearly fond of Mary and affectionate with her. Then we cut to the palace, where Queen Katherine, wife of Henry VIII (Eric Bana), has just given birth to a stillborn son. Katherine and Henry are both deeply upset. They have a daughter, Mary, but Henry wants a son to inherit the throne.
There is dancing after Mary's wedding, during which Anne tells her brother George (Jim Sturgess) that she is interested in Henry Percy, a young nobleman, even though he's already betrothed to someone else.
Thomas Boleyn and his brother-in-law discuss the king's marital troubles and lack of an heir, and speculate that he might take a mistress. They want it to be a girl from their own family, and settle on Anne.
Anne helps Mary prepare for her wedding night, tells her she's sorry she's not married so that she can't tell Mary what to expect, and demands to know all the details the next day. While Mary and William consummate their marriage (not shown), Anne's father and uncle send for her and tell her the king is coming to visit and she is to "divert" him. Anne is afraid this sort of thing could ruin her reputation, but they tell her that on the contrary, she'll probably be able to marry a nobleman when the king is done with her. Anne's mother objects to the plan, but she has no say in things.
Mary tells Anne the next day that William was "satisfactory," then admits he wasn't that great. Anne then tells Mary her news about the king.
The king arrives and is introduced to the Boleyn parents and Anne but not Mary (who is now "the other Boleyn girl"). Anne is seated next to Henry at dinner and flirts with him. Her father later tells her that everything depends on the next day's hunt. Anne flirts with Henry again, even more openly, as they prepare to leave for the hunt. But Henry comes back injured, having been thrown when he tried to follow Anne through a ravine on horseback. Anne's father is angry with her and has Mary nurse the king. As they talk while she nurses him, Mary tells him that she and her husband live in the country, by her wish, and that she urged him not to live at court for at least a year or two, but that if he wanted to go back there she would do his bidding.
Henry is taken with Mary. As he leaves, he tells her father to arrange a matter they had talked about. Mary is told that she and her husband are being given positions at court and the whole family is to go with them. She knows why and begs her husband not to let this happen, but he has weakly given in already.
Mary and Anne arrive at court and are introduced to Queen Katherine, who did not know they were coming. She asks if Mary has any special talents that might have inspired Henry to choose her for a lady in waiting -- clearly aware that this is not the case. She orders Mary to sing, to see if that is her talent. Mary tries, but it doesn't go very well. The queen dismisses them. Another lady in waiting, Jane Parker (Juno Temple), follows them and tells them that Katherine knows why Mary is here, but that Katherine is a good woman and can be trusted.
At a party that night, Anne flirts again with Henry Percy. She notes that Jane Parker is interested in George, but George doesn't return the interest, calling her something like "an ambitious little serpent." The king approaches Mary and murmurs, "Tonight." Anne looks daggers at them.
Later Anne helps Mary prepare for the evening, but she's obviously not happy about being usurped by Mary. Mary goes to the king's quarters and they talk. He says he's a good judge of people and that he likes and trusts her. He's kind to her, and eventually kisses her. She kisses back, and they have a love scene. (Not a lot is shown.)
The next morning one of Mary's father's servants, William Stafford (Eddie Redmayne), with whom Mary is friendly, takes Mary to her father to report in. He wants all the details. She says the king slept with her more than once. The family (except Anne and her mother) are pleased with how things are going.
As Mary continues her relationship with the king, and her husband is sent away from court (which Mary doesn't seem to mind), Anne sneaks off one night and secretly marries Henry Percy. They are shown in bed together after consummating their marriage. When Mary finds out, she knows Anne will be in big trouble if word gets around, because a nobleman is not supposed to marry without the king's permission. She tells her father and the couple are scolded and their marriage presumably annulled. Anne is furious but helpless. Percy is sent back home and Anne is sent to live at the French court. She's angry with Mary, but Mary insists she did it for Anne's good. Their mother tells Anne to learn from the French queen and ladies how to let a man think he's in charge, that this is "the art of being a woman."
While Anne is away, Mary becomes pregnant. This wins all kinds of titles, honors, and nice rooms in the palace for her family. Their father orders George to marry Jane Parker, even though George hates her, because she will be another good connection for them. Mary nearly miscarries and is put on bed rest, or "lying in" as it's called. Her family worries the king will lose interest in her and plots to retain their power by bringing Anne back from France to keep the king entertained. She's supposed to help keep Mary on his mind.
At dinner in the palace after she comes back, Anne is the life of the party and intrigues the king with her wit and boldness. He keeps running into her all over the place, and starts sending her jewelry, which she lusts after but always sends back. She goes to visit Mary in her room and still blames her for what happened with Percy, and for usurping her with the king. While she's in there, a servant brings another gift from the king, which Anne sends back. Mary can see by this that the king is besotted with Anne.
Anne keeps refusing to give herself to the king, saying that she doesn't want to end up like Mary, and reminding him that any child she gave him would be illegitimate and couldn't inherit the throne. When Mary has her baby, Henry is in the next room telling Anne he'll do anything for her if only she'll give him some hope. When it's announced that the baby is a boy, and Henry's attention wanders in that direction for a minute, Anne lures his attention back by telling him that he may have hope. He goes out of the room with her. Mary can see all this through the doorway. Anne's family scolds her for diverting the king's attention from the son they've been so excited about, and tells her she'd better know what she's doing.
Henry can't divorce Katherine as a Catholic, so Anne (who learned about Protestantism in France) pushes for a break with Rome. If he makes himself head of the Church of England, he can annul his marriage, marry her, and obtain an heir. Meanwhile, Anne has Mary and her son sent back to the country to live. Mary's marriage has been presumably annulled by now, for William Stafford, who has left her father's employ, proposes to her. He has a place of his own in the country now. Mary says her family wouldn't stand for it, and she's still loyal to them despite all they've done to her.
Henry decides to find some way to be rid of Katherine. She goes on trial to determine if her first marriage was consummated. (I didn't hear it spelled out in the film, but Katherine had originally been married to Henry's older brother who died. If that marriage was consummated, then Henry decided that, according to his own interpretation of biblical law, his and Katherine's marriage was invalid.) Anne is now nervous and wants Mary to come back to be by her side during the trial. Henry Percy's wife wants a divorce and is accusing him of having consummated his first marriage with Anne (which is true), which would give her grounds. The king sends for Mary and asks if this is true, saying he trusts her. If he's going to do all this for Anne, he wants to know that she didn't already consummate a marriage with someone else. The scene cuts off there, but then we see Anne later thanking Mary for lying for her. Mary says she did it as a peace offering, to heal her and Anne's relationship.
Katherine sees them on the way to her trial and has some bitter things to say to them, especially Anne. At the trial, Katherine declares her first marriage was never consummated and she's been a good wife. Later she talks to Henry privately and begs him to be again the wise king that he once was before Anne "bewitched" him. But the marriage is annulled and she is sent away.
Henry tells Anne he's torn the country apart over her. She still wants to resist him until they are married, but he forces himself on her. She cries in shock and pain.
Anne later asks Mary, "How was he with you?" Mary says he was "tender." Anne is clearly emotionally scarred by the anything-but-tender way he treated her.
Henry and Anne are married, and she is crowned queen, but she still acts like she's in a daze and no longer certain that all this was such a good idea.
Anne becomes pregnant and gives birth to a daughter, Elizabeth. She's disappointed that the baby is a girl but still loves her. Henry only says, "If we can have a healthy daughter, we can have a healthy son."
Anne gets pregnant again but miscarries. In a terrible state, she sends for Mary and George and wants them to get rid of it. George carries the dead baby out while Mary tries to comfort Anne. Anne can't bring herself to tell Henry. She's desperately afraid of what might happen if she can't have a son -- knowing that Henry is already flirting with another woman, Jane Seymour -- but she can't get pregnant again because Henry won't sleep with her while he thinks she's still pregnant, for fear of hurting the baby. She decides she needs to get pregnant by someone else and trick Henry into thinking it's his -- and then she looks meaningfully at George. (Lots of gasps and "ewwww"s from the audience.) George is shocked but then appears to acquiesce. Mary is revolted and leaves, saying, "May God have mercy on you both."
George's wife, Jane, sees Anne and George going into Anne's bedchamber. She's already jealous of George's close relationship with his sisters, especially because George never sleeps with her. Once inside the bedroom, George can't bring himself to do the deed, and Anne understands and promises him that she'll tell Henry about the miscarriage. But Jane thinks that they really did it, and tells the king.
Henry has Anne and George arrested and thrown in prison. Anne pleads not guilty at her trial, but the jurors -- including her uncle -- find her guilty. George is beheaded. (Somewhere in here, Elizabeth Boleyn, the mother of the three of them, tells her husband off over what he's done to them all, and slaps his face.) Mary, who has left the palace and has been in the country with Stafford, doesn't get back in time for George's execution, but she goes to the king afterward, once she does get there, and pleads for Anne's life. The king says he would never do anything to hurt Mary, which Mary takes to mean that Anne will be pardoned. She goes to Anne in prison. Anne asks her to look after Elizabeth, but Mary keeps trying to assure her that she will be spared. Anne asks if the king is with Jane Seymour, and Mary tells her no. Anne says it's kind of Mary to lie.
Anne is led to execution. While she addresses the crowd in farewell, Mary, watching from the crowd, is given a note. She is clearly sure it's a pardon from the king, but it's not -- it's only a message from him saying that she risked her life by appearing before him that one time, and she's not to do it again. She looks hopelessly at Anne, who takes off her headdress and necklace, kneels, and is beheaded. A shot from high above shows her body and all the blood.
Mary goes through the palace corridors to where her mother is holding baby Elizabeth. Mary tells her to hand her the child and carries her with her through the corridors.
Writing on the screen tells us that Sir Thomas Boleyn died two years later in disgrace, that his brother-in-law had three generations of his own family executed for treason, that Mary married Stafford and lived happily with him in the country, and that the daughter Anne gave Henry grew up to be a great ruler of England for some 45 years. During this last part, in an echo of the first scene, Mary and Stafford are shown strolling in the fields watching while little Elizabeth plays with Mary's own children.