As a small child I remember being told by a solemn nun that Anne Boleyn had six fingers on one hand. In the nun's eyes, it was the kind of deformity that Protestants were prone to; it was for Anne's sake, as everyone knew, that Henry VIII had broken away from Rome and plunged his entire nation into the darkness of apostasy. If it weren't for this depraved woman, England would be as holy as Ireland, and we'd all eat fish on Friday and come from families of 12.

Anne Boleyn wasn't exactly a Protestant, but she was a reformer, an evangelical; and the sixth finger, which no one saw in her lifetime, was a fragment of black propaganda directed at her daughter, Elizabeth I. In Elizabeth's reign it was the duty of beleaguered papists to demonstrate that the queen's mother had been physically and spiritually deformed. Hence, not just the extra finger but the "wen" on her throat, which supposedly she hid with jewellery: hence the deformed foetus to which she was said to have given birth. There is no evidence that this monster baby ever existed, yet some modern historians and novelists insist on prolonging its poor life, attracted to the most lurid version of events they can devise.

Anne Boleyn is one of the most controversial women in English history; we argue over her, we pity and admire and revile her, we reinvent her in every generation. She takes on the colour of our fantasies and is shaped by our preoccupations: witch, bitch, feminist, sexual temptress, cold opportunist. She is a real woman who has acquired an archetypal status and force, and one who patrols the nightmares of good wives; she is the guilt-free predator, the man-stealer, the woman who sets out her sexual wares and extorts a fantastic price. She is also the mistress who, by marrying her lover, creates a job vacancy. Her rise is glittering, her fall sordid. God pays her out. The dead take revenge on the living. The moral order is reasserted.

Much of what we think we know about Anne melts away on close inspection. We can't say for certain what year she was born, and there are many things we don't understand about how her violent death was contrived. Holbein created incisive portraits of Henry VIII and his courtiers, but there is no reliable contemporary likeness of Anne. The oval face, the golden "B" with the pendant pearls: the familiar image and its many variants are reconstructions, more or less romantic, prettified. The fact that some antique hand has written her name on a portrait does not mean that we are looking at Henry's second queen. Her image, her reputation, her life history is nebulous, a drifting cloud, a mist with certain points of colour and definition. Her eyes, it was said, were "black and beautiful". On her coronation day she walked the length of Westminster Abbey on a cloth of heaven-blue. Twice in her life at least she wore a yellow dress: once at her debut at court in 1521, and again near the end of her life, on the frozen winter's day when, on learning of the death of Henry's first queen, she danced.

When she first appeared at court she was about 21 years old, lithe, ivory-skinned, not a conventional beauty but vital and polished, glowing. Her father Thomas Boleyn was an experienced diplomat, and Anne had spent her teenage years at the French court. Even now, Englishwomen envy the way a Frenchwoman presents herself: that chic self-possession that is so hard to define or imitate. Anne had brought home an alluring strangeness: we imagine her as sleek, knowing, self-controlled. There is no evidence of an immediate attraction between Henry and the new arrival. But if, when she danced in that first masque, she raised her eyes to the king, what did she see? Not the obese, diseased figure of later years, but a man 6' 3" in height, trim-waisted, broad-chested, in his athletic prime: pious, learned, the pattern of courtesy, as accomplished a musician as he was a jouster. She saw all this but above all, she saw a married man.

Katherine of Aragon. Photograph: Getty Images

Within weeks of his accession to the throne in 1509, the teenage Henry had married a pre-used bride. Katherine of Aragon had originally been brought to England to marry his elder brother. But some four months after the marriage, Arthur died. For seven years Katherine lived neglected in London, her splendid title of Dowager Princess of Wales disguising her frugal housekeeping arrangements and dwindling hopes. Henry was her rescuer; he was in love with her, he told everyone, this was no cold political arrangement. Katherine was the daughter of two reigning monarchs: educated, gracious and regal, she had been trained for queenship and saw it as her vocation. She had been a tiny auburn-haired beauty when she came to England. Seven years older than Henry, she was shapeless and showing her age by the time Anne glided on to the scene. Katherine had many pregnancies, but her babies died before or soon after birth. Only one child survived, a daughter, Mary; but Henry needed a son. Private misfortune, by the mid-1520s, was beginning to look like public disaster. Henry wondered if he should marry again. Cardinal Wolsey, Henry's chief minister, began to survey the available French princesses.

It was only in theory, and for humble people, that marriage was for life. The rulers of Europe could and did obtain annulments, for a price, from sympathetic popes. Henry failed not because of papal high principles, but because a series of political and military events put Katherine's nephew, the Emperor Charles, in a position to thwart him. While his canon lawyers and courtiers cajoled and bribed, sweating blood to make Henry a free man, the king had already come up with an unlikely replacement for Katherine. We don't know exactly when he fell for Anne Boleyn. Her sister Mary had already been his mistress. Perhaps Henry simply didn't have much imagination. The court's erotic life seems knotted, intertwined, almost incestuous; the same faces, the same limbs and organs in different combinations. The king did not have many affairs, or many that we know about. He recognised only one illegitimate child. He valued discretion, deniability. His mistresses, whoever they were, faded back into private life.

But the pattern broke with Anne Boleyn. She would not go to bed with him, even though he wrote her love letters in his own effortful hand. He drew a heart and wrote his initials and hers, carving them into the paper like a moody adolescent. In time favours were granted. She allowed him to kiss her breasts. Her "pretty duckies", he called them. She had made the man a fool.

This, at least, was the view of most of Europe. No one dreamed that Henry would put aside a princess of Spain for the daughter of a mere gentleman. Nor could the English aristocracy credit what was happening. Long after the break with Rome, they remained revolted by Boleyn pretensions and loyal to Katherine and the pope. Anne did have the backing of a powerful kinsman, the Duke of Norfolk; her father had been lucky enough to marry into the powerful Howard clan. But for some years, the situation was deadlocked. There were two queens, the official one and the unofficial one: the king was sleeping with neither. Wolsey had been fortune's favourite, but failure to obtain the divorce cost him his career. He was exiled from court; though he died a natural death, it was under the shadow of the axe. Anne moved into his London palace. Still she kept Henry at a distance. She was, and is, credited with serpentine sexual wiles, as well as a vindictive streak that ruined anyone who crossed her. The truth may be more prosaic. Henry had decided at some point that Anne was the woman who would give him a healthy son. He wanted that son to be born in wedlock. It may have been he who insisted on self-control, and Anne who simmered and fretted.

The man who cut the knot and gave Henry his heart's desire was Thomas Cromwell, the pushy son of a Putney brewer. Cromwell had been in Wolsey's service and narrowly survived when the great man fell. In his 40s, he was a bustling, jovial man with a plain face and a busy and ingenious mind. In a land in thrall to tradition, Cromwell was in love with innovation. One of his innovations was the Church of England. If Rome won't give you a divorce, why not grant your own? Since new things had to be disguised as old things, Henry stated he was, and always had been, lawful head of the English church. Soon his subjects would be required to take an oath recognising this fact.

In the autumn of 1532 Henry and Anne crossed the channel. They stayed in Calais, an English enclave, and held talks with the French king. The weather turned foul and the English fleet was trapped in port. Henry and Anne went to bed together, and married hurriedly in a private ceremony when they were back on English soil. Anne was six months pregnant when she was crowned queen. Henry was so sure that the child would be a boy that he had the proclamations written in advance, "prince" proudly blazoned. When a daughter emerged, extra letters had to be squashed in. But Henry was not downhearted. "If it is a girl this time, boys will follow."

The psychology of the relationship between Henry and Anne is impenetrable at this distance, but contemporaries did not understand it either. The courtship lasted longer than the marriage. They quarrelled and made up, and if Anne thought Henry was looking at another woman she made jealous scenes. She was untrained in the iron self-control that Katherine had exercised. She thought, perhaps, that as Henry had married her out of passion and not out of duty, she would keep him enthralled until the arrival of a son made her status safe. But whereas duty is sustainable, passion seldom is. The discarded Katherine lived far from London, under house arrest, humiliated by her circumstances, unrelenting in her animosity to the woman who had displaced her and (as she thought) corrupted her good husband. Anne, for her part, was said to be plotting to poison both Katherine and her daughter Mary.

Aware of the reputation she trailed, Anne tried to limit the damage. She was a Bible reader, who told the women in her household to dress and behave soberly; cultured, she was a patron of scholars, and keenly interested in the reform doctrines that Henry himself would not embrace. But as Goodwife Anne, she didn't convince. Had there been lovers before the king? Gossip was rife. She surrounded herself with young men who vied for her favour. The conventions of courtly love mix with something very modern, very recognisable: a married woman's wish to test out how her powers of attraction are surviving the years. Henry was not a great lover, after all. Or so it emerged later, in a court of law. In the queen's private rooms, the young men and his wife were laughing at him: at the songs he wrote, at his clothes, and at his lack of sexual prowess and technique.

Thomas Cromwell. Photograph: Gustavo Tomsich/Corbis

At some point in 1535 Anne had quarrelled with Thomas Cromwell. Later, in Elizabethan times, it would be suggested that the idealist Anne was in dispute with the money-grubbing minister over the fate of the monasteries. The dissolution was soon to begin, and the smaller institutions were now in the king's sights. Anne, the story goes, wanted to conserve the monasteries as educational facilities. At best, this is only a partial reason for their split. Cromwell might well have retorted that the defence of the realm was more urgent. The outside world remained consistently hostile to Henry's romance and to his new title as supreme head of the church in England. No regime in Europe accepted his actions, and Rome could not be reconciled. Even Martin Luther would not give the second marriage his blessing. A sentence of excommunication hung over Henry. If implemented, it would make England a pariah nation; any Catholic ruler would be authorised to step in and help himself to the kingdom.

Anne had not risen in the world as a solitary star; she trailed an ambitious family with her. By 1535 Cromwell was outshining them all, accumulating offices of state. Anne had been his patron, but he had outgrown her, and by the spring of 1536 she had lost her value to him. It was Katherine's death that changed everything. The old queen's end was lonely. Probably cancer killed her, though rumours of poison spread when the embalmer found a black growth clinging to her heart.

When the court heard that Katherine was dead, there was celebration. It was premature. On the day of the funeral Anne miscarried a male foetus. It was her second miscarriage at least. It seemed she was no good to Henry for breeding purposes. And in the eyes of those who did not recognise his second marriage, the king was now a widower, ready to make an advantageous European match. Katherine dead, Cromwell could patch the quarrel with the emperor. This would lift the threat of crippling trade embargos, and the threat of invasion. Anne was in Cromwell's way, but he could not have acted against her alone. He might have circumvented her, discredited her, sidelined her; but it was not his business to kill her. It was Henry who was disenchanted with the woman he had waited for for so long. It was spring, and he was in love again.

What was it, this business of being "in love?" It was still rather strange to the 16th-century gentleman, who married for solid dynastic or financial advantage. The love poetry of the era attests to skirmishing in the sexual undergrowth, to histories of frustration and faithlessness; Anne's group of friends was full of part-time versifiers and one of her circle, Thomas Wyatt, made an indelible impression on English literature. But Wyatt's tone is often cynical or disappointed. There was love and there was marriage and they seldom coincided. His own marriage was wretchedly unhappy. Anne's uncle, the Duke of Norfolk, allegedly beat his wife. But the king had higher expectations. In Katherine's time he had written a song which said: "I love true where I did marry." He expected to sing this song again, and this time to Jane Seymour.

One of Anne's ladies, Jane was the self-effacing daughter of a thrusting family. She was not especially young, nor beautiful, nor witty. What did Henry see in her? The Spanish ambassador sniggered that "no doubt she has a very fine enigme"; it is an interesting way to refer to a woman's sexual organs. The ambassador did not think Jane could be a virgin after so long at Henry's court, but Henry did not doubt that this dull little woman had been waiting all her life for a prince's kiss. Anne has usually been characterised as clever and Jane as stupid, a compliant doll manipulated by her brothers and the papist faction at court. There is another interpretation possible; that Jane had observed, assessed, and seized her chance, acting with calmness and skill. Whatever her true character, her exterior was soothing. Henry and Anne had worn their quarrels like jewels. But Henry was weary. His superb athlete's body was failing him. An accident in the spring of 1536 brought to an end the jousting career in which he had taken such pride. His temper was short. His weight was increasing. He had always worried about his health, and now he had reason. In a moment of despair he had said: "I see that God will not give me male children." Jane cheered him up wonderfully; her family were numerous, and she was expected to breed.

If Cromwell devised the manner of Anne's downfall, the responsibility for it rests squarely with Henry. He was not a simple man who could be misled by his ministers. It is true he could be pushed and nudged and panicked; four years later, after Cromwell's execution, he would try to put the blame elsewhere, claiming that he had been misled. But the king was the man who gave the orders and as far as we know he never regretted Anne, or looked back, or mentioned her again after her death. The ruin of the Boleyns was sudden, compacted into a period of three weeks. Behind-the-scenes activity suggests that Henry explored the possibility of annulling his marriage and letting Anne retire, to the country or a convent; this was the way he would get rid of his unwanted fourth wife, Anne of Cleves.

But nothing in Anne's history or nature suggested she would agree to a quiet withdrawal. Like Katherine, she would go to war, and Henry did not have the patience to wait for Jane. When the arrests began, panic possessed the court. Anne's ladies, we can assume, rushed to denounce her in an effort to save themselves. Anne was not liked. On a personal level she was high-handed and difficult. She had alienated her powerful uncle, the Duke of Norfolk. Without the king's affection she was nothing. No one but her immediate family could be expected to help her. Her father did nothing, and her brother, George Boleyn, was soon locked up himself, accused of an incestuous affair with her.

Seven men were taken into custody. One of them, a nonentity, was quietly forgotten and quietly released. Another, the poet Wyatt, was Cromwell's friend. He may have saved himself by giving a statement against Anne, and no charges were made, though he was held for some time. Of the five men who would die, four had nuisance value to Cromwell; the other was collateral damage. They were personally close to the king, and this is what hurt Henry so much; the charge, which he appeared to believe, that Anne had been sleeping with his best friends.

Traitor's Gate at the Tower of London. Photograph: Graham Turner for the Guardian

When Anne was arrested and taken to the Tower she began to unravel; she talked wildly about her co-accused, repeated the words she had exchanged with them; desperate to make sense of her situation, she detailed public quarrels, the jealousies and in-fighting within her circle. Every word went back to Cromwell. He may not have had a case till Anne built it for him. Accustomed to brinksmanship, Cromwell had reached out to some unlikely allies in recent weeks: the papists, the old families who resented the Boleyns. They thought they were using him to bring Anne down, and that they could ditch him afterwards. He knew they were serving his purposes, and had every intention of ditching them.

Anne was not charged with witchcraft, as some people believe. She was charged with treasonable conspiracy to procure the king's death, a charge supported by details of adultery. It was alleged she had discussed which of her lovers she would marry after the king's death. The clear implication was that his death could be hastened. Only one of the men confessed: Mark Smeaton, a musician. In Henry's England, gentlemen were not tortured. Mark was not a gentleman. But if he was physically ill-treated, no one saw the damage; Cromwell was frightening enough, even without a rack.

Anne's supporters hate anyone who says so, but it is possible that she did have affairs. The allegations seem wildly implausible to us, but clearly did not seem so at the time. It is said that the details of the indictments do not stand up to scrutiny, that Anne could not have been where she was alleged to be on this date or that. But this misses the point. If Anne was not where everybody thought she was, that did not count in her favour. If she had risen from childbed to meet a lover, that showed her a monster of lust. It is the incest allegation that seems lurid overkill. But the 16th century did not invest incest with especial loathing. It was one of a range of sinful sexual choices. In the days when brothers and sisters seldom grew up together, genetic attraction no doubt occurred more frequently than it does in the nuclear family. If the allegations were true Anne's conduct was, contemporaries agreed, abominable. But they did not assume her innocence. Led by love or lust, people will do anything. Look what Henry had done.

The Duke of Norfolk presided over his niece's trial. Later Cromwell, who liked worthy opponents and had respected Katherine, would commend the intelligence and spirit with which Anne defended herself. But her "lovers" had already been tried and convicted, and if they were guilty, Anne must be. Henry brought in the Calais executioner to behead his wife with a sword. He may have groaned as he disbursed the man's vast fee, but the expert was worth his price. Anne's death was instantaneous.

Her head and her body were placed in a discarded arrow chest and buried in the crypt of the chapel at the Tower. But her black eyes were open wide and fixed on the future, hypnotising later generations as they did Henry. Today, we are still scrapping over the how and the why of her rise and fall. The narrative of her destruction, though partial, is vivid and terrifying. "I have only a little neck," she told the Constable of the Tower. And, he reported, she put her hands around her throat. And laughed.