Before Harry Potter, before the novels, before the films, before the millions and millions of pounds, there was a little girl who liked to play witches and wizards. During the sleepy summer months, in the English town of Winterbourne, a half-hour journey by car from Bristol, Joanne Rowling, then six years old, first encountered a wizard called Potter. The game of Let's Pretend was played out in the front garden of number 35 Nicholls Lane, one of a row of grey brick, three-bedroom houses, into which Pete and Anne Rowling and their two young daughters had recently moved. The game was Joanne's idea and involved raiding her mother's cupboard for costumes, the neighbours' garages for brooms and corralling the children next door to make up the numbers. Joanne, her younger sister Dianne and friend Vikki were all witches while the solitary wizard was five-year-old Ian Potter. As he remembered almost 30 years later: "I used to wear my Dad's long coat back to front to look like a wizard. I think there were a pair of joke specs in the box as well - a bit like Harry's."

The life of J K Rowling began with the meeting of two strangers on a train in 1964. Pete Rowling was an 18-year-old soldier when he met Anne Volant, a WREN, also 18, on the train from King's Cross bound for the headquarters of 45 Commando in Arbroath. Introductions across the seated compartment led to a long conversation and stolen kisses beneath duffel coats. By the time they alighted in Scotland, Pete and Anne were a confirmed couple. A few months into their courtship Anne became pregnant with her first child, Joanne. The young lovers decided to discard their uniforms to marry on 14 March 1965 before setting up home in Yate, ten miles outside Bristol. Four months later, on 31 July 1965, their daughter was born at the Cottage Hospital, in the more affluent suburb of Chipping Sodbury, where Rowling would later claim her family lived. While her father secured employment as an apprentice engineer at a Bristol factory, her mother cared for Joanne and her sister, Dianne, born two years later on 28 June 1967. A year later the family moved to the larger house at Winterbourne, where Joanne first discovered the magical world of books, and created her own adventures in the front garden.

A childhood bout of measles, at the age of four, provided the author's earliest memory of books, when her father raised her spirits by reading aloud to his bed-bound daughter the adventures of Toad of Toad Hall, from The Wind in the Willows. Books were spread around the house, crammed in every room and although young Joanne had little interest in the adventures of the Famous Five, she would later praise the work of Richard Scarry, whose anthropomorphic work inspired her earliest work of fiction: a story called "Rabbit" written at the age of six. By this time she was a happy pupil at St Michael's Church of England school, five minutes' walk from the family home. But another move was afoot. In 1974 her parents purchased an old stone cottage in Tutshill, on the Welsh border, close to the Forest of Dean, which would become a blueprint for Harry Potter's Forbidden Forest, just as it had inspired the work of another local author, the late Dennis Potter.

The idyllic Church Cottage, which had a flagstone floor and a covered well, was just a goblin's throw from the local graveyard, and was surrounded by countryside in which the Rowling sisters would enact their adventures. But for the young JK Rowling, the first day at Tutshill Church of England school in September 1974 was not a success. She scored only half a mark out of ten in a test that led to her being positioned on the less intellectual side of the class. Her natural ability soon shone through and she was promoted, but as she explained: "the promotion was at a cost ... Mrs Morgan made me swap seats with my best friend." The teacher, Mrs Sylvia Morgan, was a strict, intimidating woman, who frightened Joanne as a child and whose presence would work its way into the less sympathetic masters of Hogwarts. By the age of ten, Joanne was a keen Brownie, a voracious reader and a serious student who raced to get her hand up first. "I was the epitome of a bookish child, short and squat, thick National Health glasses, living in a world of complete daydreams."

When she made the move to secondary school, Joanne found herself accompanied by her mother. After 12 years bringing up her daughters, Anne Rowling secured the position of lab technician at Wyedean Comprehensive under the supervision of John Nettleship, the school's head of science. Nettleship remembers Joanne, whom he taught, as a bright but quiet girl and considers himself an early inspiration for Professor Snape. "I think chemistry maybe made the most impact on her because I did teach her about the philosopher's stone, the alchemist's stone. Possibly she knew about it already, but I did include it in my lessons and explained how it turned things to gold." He then chuckles before adding: "It seems to have worked for her, hasn't it." Although bright, she was not the most enthusiastic student, as Nettleship, who is now retired, recalls: "Her attitude in the science lessons was more like Harry's in the potions class rather than Hermione's."

Anne Rowling, meanwhile, was delighted to be around the beakers and chemicals and working once again after such a long absence. "She was absolutely brilliant, a sparkling character, totally reliable, very interested in words and stories and things like that. Although her job was on the technical side, she was also very imaginative," says Nettleship. A brief encounter with bullying led Joanne to spend her break walking to the science block to collect her dinner money, rather than face the intimidating atmosphere of the playground. A larger girl in her own year picked a fight with her. "I didn't have a choice. It was hit back or lie down and play dead. For a few days I was quite famous because she hadn't managed to flatten me. The truth was, my locker was right behind me and it held me up."

Throughout her teens Rowling honed her taste in reading material. It is unsurprising that she was greatly influenced by JRR Tolkein's The Lord of the Rings but she also loved Jane Austen, whose work Emma she has read over 20 times. Another seminal influence was Jessica Mitford, whom she adopted as a personal heroine, and whose biography, Hons and Rebels, became a significant text for Rowling.

But as with all teenagers, Rowling became more and more interested in pop music. It was the early 1980s and so she was inspired by The Smiths and Siouxsie Sioux, whose look she adopted early on and maintained for many years; when she began university she still sported startling back-combed hair and heavy black eyeliner.

At this point Rowling's home was a happy and stable environment. Her father, Pete, was now an executive engineer at the Rolls Royce plant and her mother was working in a job she adored. But things were about to change dramatically, casting a shadow over Rowling's life and tearing apart her close-knit family.

'Home was a difficult place to be' - JK Rowling on Desert Island Discs

The spectre of her illness first appeared to Anne Rowling in 1978 when her hand began to tremble while she poured tea. At first the symptoms were fleeting and she dismissed them with a shrug but over the next two years her loss of physical control intensified. She began breaking beakers at work and often dissolved in tears of frustration. On a good day she could still play guitar, but the bad days began to mount up. When Joanne was 15, her mother was finally diagnosed with multiple sclerosis. The disease was triggered by the lack of a certain protein in her spinal column which served to scramble the signals from her brain and resulted in a loss of control of her limbs. Anne was broken-hearted at having to give up her lab technician's job, but busied herself by volunteering to clean the local church. Rowling could only watch helplessly as her mother succumbed to this destructive disease. In an article the author wrote in Scotland on Sunday, she described how at one point her mother was reduced to crawling upstairs. The "galloping" progression of the illness meant that within a few years Anne Rowling moved from walking with difficulty to using a walking frame and wheelchair.

A depression settled over Church Cottage, leaving Rowling feeling trapped and miserable. Escape came in the form of a new pupil at Wydean Comprehensive, Sean Harris, who quickly became a firm friend. In 1982, he drew up outside the family home in his blue Ford Anglia and whisked her away from the grim stillness of Tutshill to the concerts and bars of Bristol. He would park under the Severn Bridge and together the pair dreamt up better futures for each other. Harris's blue Ford Anglia would become immortalised in Rowling's fiction as Ron Weasley's family car and he would be described in the dedication in her second book as "getaway driver and foul weather friend".

Joanne's academic achievements led to her being appointed Head Girl at Wydean and her ambition was to study languages at Oxford. Her A-levels in English, French and German (two As and a B) were good enough on paper to secure an Oxbridge place, but she wasn't accepted. Her teachers were surprised, believing she was the victim of institutional prejudice against comprehensive pupils. The dreaming spires of Oxford were instead replaced by the red-brick halls of residence at the University of Exeter.

Lecturers remember Rowling as nervous and insecure, but a fellow student, Yvette Cowles, told Sean Smith, her biographer, that she was popular and striking. "She wore long skirts and used to have this blue denim jacket she liked to wear. Jo was very shapely and she had this big hair, kind of back -combed and lacquered, and lots of heavy eyeliner. I think she was quite popular with the guys." In her first year she signed up for French and Classics but an attitude to academia best described as minimum work, maximum fun led to her abandoning Classics after she failed to register properly for an exam. Her third year was spent teaching in a school in Paris and sharing a flat with an Italian, a Russian and a Spaniard. She found the Italian disagreeable and would avoid him by spending whole days in her room reading. During this time she read Charles Dickens' A Tale of Two Cities, a literary discovery that may have influenced her alleged intention to kill off Harry Potter at the end of book seven. The death of Charles Darnay, sacrificing his life for a friend, and his moving last words had a major impact on Rowling: "It is a far, far better thing that I do than I have ever done; it is a far, far better rest that I go to than I have ever known."

Anne Rowling attended her daughter's graduation in 1987 in a wheelchair and watched with pride as she was awarded a 2: 2 in French. The next four years were to see her daughter work through a variety of temporary jobs including posts with Amnesty International and the Manchester Chamber of Commerce, a post so brief there is no record of her ever being there. During this time she began a parallel life as a writer, toiling over two adult novels which were never published, and developing a passion for classical music. It was while Rowling drifted aimlessly through these years that the most important moment of her life occurred. In summer 1990, Rowling's boyfriend had moved to Manchester and she found herself returning to London by train after a weekend spent flat-hunting with him. Quite spontaneously during that trip an idea took shape: "All of a sudden the idea for Harry just appeared in my mind's eye. I can't tell you why or what triggered it. But I saw the idea of Harry and the wizard school very plainly. I suddenly had this basic idea of a boy who didn't know who he was, who didn't know he was a wizard until he got his invitation to wizard school. I have never been so excited by an idea."

The birth of Harry Potter was followed six months later by the death of her mother. Anne Rowling passed away on 30 December 1990 at 45. Joanne had visited home six days earlier but had not realised the seriousness of her mother's illness. "She was extremely thin and looked exhausted. I don't know how I didn't realise how ill she was, except that I had watched her deteriorate for so long that the change, at the time, didn't seem so dramatic." The death of her mother sent Rowling into a tailspin. Within months her relationship ended, she moved into a hotel and would soon leave the country altogether.

An advert in the Guardian for English teachers in Portugal held out the promise of warmth and a fresh start. Rowling was soon living in the bustling city of Porto in a shared flat with Aine Kiely, from Cork, and an English girl, Jill Prewett. Between 5pm and 10pm the trio taught classes at the Encounter English School before heading out to Swing, the town's largest nightclub. Rowling spent her days in local cafes, sipping strong coffee and writing in longhand the first draft of the first Harry Potter. Maria Ines Augiar was the school's assistant director and became a close friend, remembering Rowling as a "very nervous person, anxious" and one who was "desperate for love." Only after she had been resident in the country for 18 months did Rowling find love, albeit briefly, with Jorge Arantes, a dashing journalism student three years her junior.

Arantes was drinking with friends in Meia Cava, a downstairs bar when, as he recalled: "This girl with the most amazing blue eyes walked in." He approached her and began to chat in English and found they were both fans of Jane Austen. The night ended with an exchange of kisses and phone numbers and within a couple of days they were sleeping together. But if Arantes, who had an abundance of Latin machismo, thought he could treat her in a casual manner, he was mistaken, as his new girlfriend made clear when he began chatting to other girls while they were on a date. Rowling approached him and whispered in his ear that it was her or them. She won that contest, but a volatile passion came to exist between the pair. Against the odds their relationship continued, with Rowling providing money through her work, which Arantes spent while looking for employment he never seemed to find.

The couple had been together for only a few months when Rowling became pregnant, just as Arantes embarked on eight months' national service. They agreed that Rowling would move in with Arantes's mother, who lived in a small two-bedroom apartment on the rua Duque de Saldanha, and await his return. Unfortunately the pregnancy ended in miscarriage. The disappointment brought them closer together and on 28 August 1992 Arantes proposed. Friends in Portugal were taken aback when Rowling accepted. Maria Ines Augiar believed Jorge to be both possessive and jealous, while Steve Cassidy, who ran the school where Rowling worked, viewed him as rough and untrustworthy. His perception was not altered by an incident at the language school prior to their wedding. The couple had been drinking coffee in a cafe across the street when an argument broke out during which Jorge violently pushed his fiancee. Rowling burst into tears and ran back to the school, but the intensity of Jorge's outburst led one onlooker to inform the police, who arrived to find a large crowd surrounding Arantes as he cried: "Joanne, forgive me, I love you." According to Maria Ines Augiar, Rowling was soon shouting back: "I love you, Jorge."

The marriage lasted 13 months and one day. Later, when Rowling was writing Harry Potter and The Prisoner of Azkaban, she had one character, Professor Trelawney, inform a pupil that the thing he was most fearful of would take place on 16 October - the date of her wedding in 1992. The ceremony took place in Porto's registry office and was attended by Rowling's sister, Dianne, and her boyfriend. Photographs suggest a subdued affair with Rowling in black holding a bunch of deep red flowers. The girls' father did not attend. The speed of his decision to move in with his secretary, after his wife's death, distressed both sisters and a fault-line now separated them and their father.

The marital home remained that of Arantes's mother and was far from happy. Two months after the ceremony Rowling found herself pregnant once again. She continued her job and, worryingly, discovered she was losing weight due to the stress of arguments with Arantes. Prior to the birth of her daughter, Jessica, named after Jessica Mitford, on 27 July 1993, Rowling's friends were urging her to leave her husband, but she was determined to make her marriage work. Arantes's behaviour made this impossible. Rowling has never spoken publicly about her marriage, except to dismiss her former husband's claims to have helped shape the first Potter novel, with the withering line: "He had as much input into Harry Potter as I had in A Tale of Two Cities."

But Arantes has described his shameful and violent behaviour. The extent of the domestic violence Rowling endured is not known, but Arantes admits slapping her "very hard" early in the morning of 17 November 1993 and throwing her out of the house without her daughter. When Rowling returned the following day with Maria Ines Augiar, a policeman accompanied them and it did not take long before Jessica was handed over.

For two weeks Joanne and Jessica stayed in hiding with friends whom Arantes did not know. Then she boarded a flight to Britain and flew from Arantes and his terrifying temper. Her precious cargo included a cherished daughter and three chapters about Harry Potter, her surrogate son.

Trains run through JK Rowling's life with time-tabled frequency. Her parents met on a train, the idea for Harry Potter was first conceived on a train and now in the winter of 1993, a train carried both mother and daughter north towards a new life in Scotland.

After arriving back in Britain, Rowling had nowhere else to turn. Her father had re-married Janet Gallivan, his secretary, and relations were strained, but Dianne had recently married in Edinburgh and swung open her door. Despite her sister's hospitality, the next few years were to be Rowling's nadir. Although never quite as bad as the press has painted in terms of poverty - she always had food and clothes, heat and light - Rowling did endure a deep depression brought about by circumstance and frustration.

For the first few weeks Rowling and her daughter stayed with her sister Dianne and restaurateur brother-in-law, Roger Moore, in their home in Marchmont Road, but it was an arrangement that could not continue indefinitely. A small flat at 28 Gardner's Crescent was organised by social services. So began Rowling's experience of government bureaucracy as she was forced to fill in endless forms and attend demeaning interviews in order to secure a weekly allowance of GBP 69. A Christmas present she received only added to the gloom. REM's new album, Automatic For The People, was viewed by critics as their nihilistic best and Rowling seized on the spirit-sapping track, Everybody Hurts, which she began to play incessantly.

The New Year brought with it a new flat, but her depression deepened. Shortly after her return to Britain her old friend Sean Harris had offered to lend her money, but she refused. By mid-winter she was so unhappy in Gardner's Crescent that she changed her mind and borrowed GBP 600 from him to use as a deposit on a rented flat.

Finding one was more difficult than she thought and it was only after enduring rejection after rejection from owners unwilling to rent to an unemployed single mother, that she secured the keys to a flat in South Lorne Place. It was a harled and brickfaced four-storey flat, furnished thanks to contributions from friends. It was here that Rowling was overcome by a feeling of hopelessness.

Her despair was compounded by the arrival in March 1994 of her estranged husband in search of his wife and daughter.

Since her departure from Porto, Arantes had succumbed to drug abuse and his wife was so concerned for the safety of her and her daughter that she was forced to obtain an Action of Interdict - an order of restraint that prevented Arantes from molesting, abusing her verbally, threatening her or putting her in a state of fear and alarmby using violence towards her anywhere within the sheriffdomof Edinburgh.

Arantes returned to Portugal and Rowling filed for divorce in August 1994.

The sense that she was failing her daughter was unbearable to Rowling. Whenever she visited the homes of other mothers, Rowling gazed covetously at their children's bright bundles of toys. Her own daughter's toys could fit comfortably into a shoe box. Yet when an insensitive, if wellmeaning, health visitor brought around a raggedy teddy-bear and a small plastic phone she binned them in a fit of shame.

Only after a period of counselling was she able to tackle her depression and begin writing again. But once she did, it was the writing that elevated her self-worth. The first three chapters of Harry Potter and the Philosopher's Stone had made her sister laugh, a reaction that kindled hope in Rowling.

In the long evenings at home, with little else to do, she set about working on further chapters. In the mythology of JK Rowling, Nicolson's restaurant is where the majority of Harry Potter was written. Yet the brightly coloured restaurant has now gone, long since replaced by a Chinese restaurant, the Buffet King. The new owner, Winnie Yau still receives pilgrims from all over the world, asking about the building's most famous customer.

Rowling went to Nicolson's either as a respite from a freezing flat or through a passion for good coffee, depending on which version you believe. Nicolson's was scarcely convenient, half a mile from her flat and at the top of 20 steps, quite a hike for a mother with a young child in a push-chair, but it was owned by her brother-in-law which allowed her to draw out a single coffee over a few hours, and the primary colours in which it was painted couldn't help but lift even the most despondent visitor. A second establishment she visited regularly was the Elephant House, on George IV bridge, whose much patronised back room has windows overlooking Greyfriars cemetery.

A sign at the entrance now reads: Experience the same atmosphere that JK Rowling did as she mulled over a coffee, writing the first Harry Potter novel.

The writing of Harry Potter and the Philosopher's Stone was slow. Rowling wrote in long-hand then typed up the finished work on a second-hand manual typewriter. In the meantime she needed a job. At first she took on secretarial work for a few hours each week, but a full-time job was a necessity. She wanted a career, not just a means to make money and so applied to study for a postgraduate certificate of education in modern languages at Moray House, now part of Edinburgh University. A small grant was supplemented by a generous friend and in August 1995 she became a student once again. Staff at St David's High School on Dalkeith Road and Leith Academy, where she taught as part of her teaching training, remember her as keen and well-organised.

She graduated in June1996 around which time she heard the news that Harry Potter was to be published at last.

'The purest most unalloyed joy was when I finally knew it was going to be a book, a real book you could see sitting on the shelf of a bookshop' - JK Rowling

When the manuscript of Harry Potter and the Philosopher's Stone was finished, early in the New Year of 1996, Rowling visited Edinburgh Central Library to look up the Writers' and Artists' Year Book in search of a literary agent. Her first approach had been unsuccessful: a brief rejection letter. She then posted a sample of three chapters and a covering letter to Christopher Little Literary Agents, based in Fulham. It was here that a young reader, Bryony Evans, read the first chapter and laughed. Evans passed the chapters to Fleur Howle, a freelance reader, who agreed with her assessment and together they persuaded Little to sign up Rowling. A few days later Rowling received a letter asking for the remainder of the manuscript. The agency sent Rowling's 200-page script to 12 publishers, all of whom, to their eternal regret, turned down the book. Harper Collins showed interest but was too slow in formulating a bid and so the first book by the most lucrative writer in the world was picked up by Bloomsbury for an advance of GBP 1,500.

When Barry Cunningham, head of children's fiction at Bloomsbury, invited Rowling to lunch in London, he praised her book but told her to be prepared as there was no financial reward in children's books. Rowling did not care. To hold a hardback copy in her hand was reward enough. Yet prior to publication she would prove him wrong.

Anxious to finish the second novel, Harry Potter and the Chamber of Secrets, Rowling applied for a grant from The Scottish Arts Council and was awarded GBP 8,000 that allowed her to purchase a word processor and steady her turbulent finances. The publication date for Harry Potter and the Philosopher's Stone was set at 26 June 1997 and Joanne Rowling was re-christened JK Rowling. Christopher Little had discovered that boys were unlikely to read a book written by a girl and so pushed for Bloomsbury to use the ambiguous initials in order to attract both sexes.

But before Harry Potter and Hagrid, Hermione and Ron Weasley, Professors Albus Dumbledore and Severus Snape could bewitch the children of Britain, they had cast a collective spell over an American publisher. Arthur Levine, the editorial director of Scholastic Books, a large American publishing house, first read the novel at 36,000ft as he flew over the Atlantic to attend the Bologna Book Fair. He became so engrossed that he had no wish to land. Little had organised an auction for the American publishing rights to Harry Potter and Levine became determined to be the highest bidder. Three days after the British publication Rowling received a call from her agent to say that Scholastic had bid $100,000 - an unprecedented sum - for a children's book that already had the makings of a phenomenon.

In the autumn of 1999 JK Rowling arrived in America for yet another nation -wide tour. The Prisoner of Azkaban, her third novel in as many years, had just been released three months after its British edition, a delay that had caused thousands of eager Americans to order Bloomsbury editions over the internet. Her American publishers, Scholastic, were anxious to develop Rowling's profile with a series of book signing sessions. Previous tours in 1997 and 1998 had seen the number of excited children and patient parents rise from dozens to a few hundred. No one expected to see thousands. As one store manager later explained: "It's the nearest I've ever seen to Beatlemania with books."

When Rowling's black Lincoln arrived at Politics and Prose, a popular Washington book store, and Rowling saw a queue that snaked out the door and two blocks back, she assumed there was some kind of sale. On that visit she managed to sign 1,400 copies before her handlers dragged her on to the next event. The same delighted crowds of children and, for the first time, unaccompanied adults, met her at every city on the tour. Chat show hosts such as Katie Couric of the Today Show and Rosie O'Donnell were delighted to share their sofa with the hottest author in America.

In the season of Hallowe'en, Harry Potter reached critical mass and exploded. Across the country six giant printing presses were spinning 24 hours a day to maintain demand for his three adventures. The New York Times had JK Rowling at the first three slots on their bestseller lists and would eventually have to a create a new children's book list in order to evict her. Time magazine placed the boy wizard in the company of world leaders when it granted him a cover story. When embarking on the writer's life, the height of Rowling's ambition was for a sales assistant to recognise her name off her credit card and declare herself a fan. "In my wildest fantasy I could not have imagined anything like this," she told Katie Couric on the Today Show that autumn. "I could not even come close."

In Britain the books had been a slow steady burn. Harry Potter and the Philosopher's Stone had a first print run of 1,000 copies, but Bloomsbury knew they had a hit when new orders began to arrive and the book ran into reprint after reprint. British sales had been assisted through the publicity generated by her $ 100,000 advance in America. Although in later years Rowling would have cause to regret her portrayal as "poverty-stricken single mum makes good", those stories gave her a profile most first-time authors could only dream about. Yet all the hype and publicity would have faded like the steam off a cauldron if children had not grasped the books as their own. Teachers and parents who presented the novel to their children could almost hear an audible "click." They got Harry Potter and they wouldn't let him go. The first Harry Potter sold 70,000 copies in the first year and won the Smarties Prize for Children's Literature.

The $ 100,000 from Scholastic for the American rights had allowed Rowling to purchase a two-bedroom flat in Hazelbank Terrace. Jessica soon settled into Craiglockhart Primary School and a nanny was hired to allow Rowling extra time to write and attend signings and readings. While Rowling remained nervous and unsure around adults and particularly during interviews, she adored visiting schools and attending children's events. By the time her second novel, Harry Potter and the Chamber of Secrets was released in June 1998, an anxious audience was already waiting. The book became a number one bestseller and the hype continued to build, this time infecting adults who overcame their embarrassment to lose themselves in a pacy, humorous read. In order to lasso a wider audience and spare the blushes of commuters, Bloomsbury released the books with moody adult covers.

Rowling's ambition was to release one book a year for seven years, taking young Harry up to graduation and no further. By the time the Prisoner of Azkaban was released in June 1999 Rowling was on the verge of her first million and had maintained her tight writing schedule. She had also taken the next step towards ensuring her creation's global dominance - a film deal with Warner Brothers had finally been agreed. An executive at Heyday Films, Tania Seqhatchian, had read the first Potter book, spotted its potential and passed it onto her boss, David Heyman, an experienced producer who was representing the Hollywood studio in Britain.

Christopher Little, Rowling's agent, was aware of the tremendous potential in the film-rights and urged a slow, cautious approach, while the author herself was highly protective. "I would do everything to prevent Harry Potter from turning up on fast food boxes," explained Rowling. "That would be my worst nightmare." The deal Rowling finally consented to gave her unprecedented powers for an author, who is usually handed a cheque with one hand and shown to the door with the other. Under the deal she took a lower fee, said to be around $ 1 million, but had veto on the director, the script and merchandising ideas.

Rowling showed she shared the pluck of Harry Potter when she disagreed with Steven Spielberg, who took an interest in directing the film. The director of ET and Raiders of the Lost Ark wished to merge the plots of the first two books and cast Haley Joel Osment, the American child actor who starred in The Sixth Sense as Harry Potter. Rowling insisted each film tackle one book and that Harry had to be British. Spielberg walked away.

The Harry Potter phenomenon was to be driven by America, where 55 per cent of all Rowling books are sold, and it was there, at the buckle of the bible belt, that the backlash began. In autumn 1999 the board of education in South Carolina agreed to review whether the novels should be available in schools after receiving complaints from parents. One outraged mother criticised them for possessing "a serious tone of death, hate, lack of respect and sheer evil." A few Christian schools in Australia banned them on account of their tone, but the Catholic Church later rode to their defence and praised them for instructing children on good and evil. For the feminist academic, Dr Elizabeth Heilman, the trouble was not broomsticks, but boys. The males were forever rescuing the females, who, she believed, were "giggly, emotional, gossipy and anti-intellectual." It was a charge Rowling dismissed out of hand. The more serious charge of plagiarism levelled by Nancy Stouffer required the judgement of the American courts.

Stouffer was the author of The Legend of Rah and the Muggles, a children's book published in 1984 that featured a hero called Larry Potter, who also had black hair with glasses. In her book Muggles were imps, in Rowling's work it is a term given to ordinary non-magic folk - but still Stouffer believed she was the inspiration for a now mutli-million dollar success story. Rowling defended the case through the courts and was vindicated in September 2002.

By the time Harry Potter and the Goblet of Fire was published in July 2000, Rowling was struggling to cope with her new status. The pressure to complete her longest novel to date had been intense, compounded by a plotting error that forced her to rip-up chapters and begin again. The manuscript was delivered in March and so concerned were her publishers about plot leaks that it was placed in a safe. Bloomsbury's marketing campaign meant no copy was available to anyone prior to the publication date, 8 July, and even the title was a closely guarded secret, to be revealed as part of a slow press campaign. The result was the fastest-selling book in Britain, where one million copies were eventually sold. The book sold more than five million in America.

The success of her books had made Rowling inaccessible to fans. Book signings were increasingly difficult due to the volume of demand. When Bloomsbury converted King's Cross into Platform 9 3/4 from which the Hogwarts Express departs in her books, Rowling was unable to meet the children who had gathered because of the press scrum and could only shout an apology out the window as the antique train hired for the event steamed off. She had greater success at communicating her message at Exeter University, where she returned that summer to collect an honorary degree, urging the students never to fear failure.

Rowling's success in cash terms was staggering. The Sunday Times Rich list of 2001 estimated her wealth at GBP 65 million, a sum Rowling used to insulate herself from the world. The small flat in Hazelbank Terrace was donated to a close friend, a fellow single-mother, while Rowling and Jessica moved into a Georgian mansion in Merchiston whose eight feet high wall would deter even the most intrusive snooper. She also paid GBP 4.5 million for a second home in London's Kensington, complete with indoor swimming pool. A country house on the banks of the River Tay called Killiechassie was added to her property portfolio in 2001. In previous years Rowling was regularly spotted around Edinburgh in cafes and restaurants, but her success restricted her movements to dinner parties with friends. When Giles Gordon, the literary agent, announced in his column in the Edinburgh Evening News that the author regularly frequented Margiotta, the popular city deli, Rowling never returned.

The next stage of the Potter phenomenon was triggered by the success of the first film, Harry Potter and the Philosopher's Stone. Rowling approved Chris Columbus as director and was delighted by the casting of Daniel Radcliffe as Harry and pleased that Robbie Coltrane had accepted the role of Hagrid. Writing on the next book was set aside as she discussed set designs and script notes, and watched rushes on what would become, after Titanic, the second -biggest film of all time grossing $ 926 million and creating millions of new readers. Escorting Rowling to the premieres in London and Edinburgh was Dr Neil Murray, an anaesthesiologist whom she had met at a friend's dinner party. Murray, then separated from the wife whom he later divorced, brought love and a new balance into Rowling's life.

The couple married on Boxing Day 2001 in a private ceremony at Killiechassie attended by close friends and family including her father, with whom relations had thawed, and his second wife. The couple's first child, a boy, was born in March 2003 and the world breathed a sigh of relief when it was announced he would be christened David and not Harry.

There are now only four days to endure before the publication of Harry Potter and the Order of the Phoenix and Rowling can gaze with considerable pride on what her work has achieved. In just six years more than 160 million Harry Potter books have been sold in more than 100 countries, both films have achieved box office records and a Harry Potter duvet set brought a little financial light to a despondent Marks & Spencer. Harry Potter licensing deals have been struck with the biggest companies in the world, with Coca-Cola bidding GBP 65 million for the rights. Next week Rowling will become the first artist since Madonna to participate in a live-webcast at the Albert Hall, at which 4,000 children have the chance to ask her questions as Stephen Fry tries to contain them. Even Prince Charles has swooned in her presence, commenting: "I'm staggered that someone can write so beautifully."

The tragedy for fans is that they are one book closer to the end. The final chapter has already been written and is tucked in a yellow folder in an anonymous safety deposit box. We may think we're experiencing a literary phenomenon - but just wait until that box is unlocked ...

It was, she later said, "the best moment" in "one of the best weeks of my life." It was the summer of 1998, and JK Rowling was touring the country reading extracts from her second book, Harry Potter and the Chamber of Secrets. She had just finished a reading and the children had begun to drift away when a mother approached her for a quiet word. She explained that her nine-year-old son was dyslexic and Harry Potter was the first book he had ever managed to finish on his own. "She said she'd burst into tears when she found him reading it in bed the morning after she'd read the first two chapters aloud to him." Rowling recalled. "I'm not sure I managed to convey to her what a wonderful thing that was to hear, because I thought I was going to cry too."

That scene has since been repeated in bookshops, libraries and schoolrooms across the globe, as the adventures of Harry Potter have drawn an entire generation, previously bewitched by television and computer games, back to the traditional comfort of a book. Rowling's Harry Potter novels have been a godsend to teachers and parents who feared they could not open a book in front of a child without evoking a yawn. This love of reading in young children is part of a long legacy spawned by the Harry Potter books and by Rowling herself. It has been noted, too, that Harry Potter has become a trusted guide through the difficulties of childhood, tackling fears, death and disappointment in a most admirable manner.

"We cannot sing the praises of Rowling high enough," says Charlie Griffiths, director of the National Literacy Association. "Anyone who can persuade children to read should be treasured and what she's given us in Harry Potter is little short of miraculous. To see children queuing outside a store, not for concert tickets or computer games, but for a book, is brilliant."

Griffiths says that the books themselves rise above the massive publicity campaigns that now surround the release of a new Harry Potter book.

"I know people will insist it's all down to clever marketing, but if there is not a story that a child wants to read then no amount of marketing will persuade them. Her novels have created positive peer pressure in favour of reading. A child might not have that great an interest in reading but he wants to keep up with his friends and so he'll get sucked in. She's also helped shine a light on other wonderful children's writers."

The works of Jacqueline Wilson, Philip Pullman, Lemony Snicket and Eoin Colfer have all been given a boost by young readers who, having torn through the four Potter novels, are anxious to kill time before the release of the fifth. In an unprecedented reversal, Harry Potter has also been responsible for the swelling hordes of adults reading children's literature. It is unlikely, for example, that Sir Tom Stoppard would be scripting an adaptation of Pullman's Northern Lights trilogy were it not for the interest in children's fiction triggered by Rowling. Children remain her principal audience, though, and there is no way to quantify the sheer delight and happiness she has brought to their lives. As one Scots mother explained it: "She's made bedtime less of a struggle than it once was and for that alone I'm grateful."

But Rowling is determined that her legacy will encompass more than book sales and pencil cases. It will be to make a difference to the lives of those who struggle. She's determined to reduce the stigma attached to single mothers, ease the pain borne by MS sufferers and simultaneously raise their standard of care. She has said she will not be satisfied until Scotland has a chain of centres designed to comfort and support those with cancer. She has invested her publicity, time and generosity into issues she can relate to, rather than adopting a scattergun approach. Today she is a patron of three charities; the National Council for One Parent Families, the MS Society of Scotland and Maggie's Centre.

To One Parent Families she donated GBP 500,000 and in September 2000 accepted an offer to become their ambassador, a role she has taken to heart. Far more valuable than her money is her time and the attention she can draw to an issue often neglected. An article she wrote for the Sun newspaper attacked the public perception of single parents as careless teenagers, pointing out that 60 per cent are separated, divorced or bereaved. "We are all doing two people's jobs single-handed before we even start looking for paid work and, as I found out the hard way, we have to fight twice as hard to get half as far," she wrote.

When Ann Widdecombe had the temerity to suggest that married couples were the norm, Rowling retaliated in a speech at a charities conference attended by Gordon Brown. "We may not be some people's preferred norm but we are here," she declared, before adding: "We should judge how civilised a society is not by what it prefers to call normal but by how it treats its most vulnerable members." The author has continued to support the organisation even though her second marriage means she no longer falls into the category.

Personal experience of the assistance Edinburgh's Maggie's Centre provided to a friend with breast cancer led her to offer her patronage to the organisation. The aim of Maggie's Centres is to provide cancer sufferers a place where they can receive information and support. Situated close to hospitals that provide treatment, plans are currently afoot to build another six across Scotland. By attending charity functions and organising readings, Rowling has helped raise thousands of pounds for Maggie's. Marie McQuade, the charity's fundraiser, says her backing is invaluable. "Her endorsement has raised awareness and we're delighted with her support." As Rowling declares in the centre's annual report: "I saw with my own eyes the difference that Maggie's Centre made to a very good friend of mine."

The charity to which she has the strongest bond, however, is the MS Society of Scotland. It is a cause close to her heart. Rowling's mother was crippled by the disease and it eventually killed her. She donated a large sum to help fund a senior fellowship in MS research at Aberdeen University, and last year she hosted a Halloween ball at Stirling Castle which raised GBP 280,000.

Of deep concern to Rowling is the fact that Scotland has the highest MS rate in the world, twice that of England and Wales, for entirely unknown reasons. There is no national standard of care with treatment varying wildly across the country, and a crucial drug entitled beta-interferon is under-prescribed. "She's in it for the long haul," says Mark Hazelwood, director of MS Scotland. "She has a deep and personal concern about MS because she has experienced how it affected her mother. She may attract press and publicity when she visits our centres but when the media have moved on she stays for a few hours just talking to people and I think that says a lot."

Rowling's legacy stretches to the cinema too. The Harry Potter movies could yet be the most successful series of films in history. If Warner Brothers continue to produce a film for each book, the result could be $ 5 billion in box office receipts and billions more in merchandise and DVD sales. Daniel Radcliffe, the actor who plays Harry, is set to bow out after the third film, but a substitute will be secured and the magic will roll on. The Harry Potter film franchise is a gravy train that will not be derailed. This level of success in film and literature is unparalleled. JRR Tolkien was dead for decades before the Lord of the Rings trilogy was released, and Ian Fleming saw only Dr No before he died, while other bestselling authors such as Stephen King have seen adaptations of their work flop at the box office. In a decade's time a boxed set of all seven films is sure to be a feature in many homes, as traditional at Christmas as The Wizard of Oz or It's A Wonderful Life.

It now looks likely that Rowling will live to see her net worth surpass GBP 1 billion, the first author ever to do so. But she is grounded enough to know that her most personal legacy remains her two children. Her success in shielding her daughter Jessica, who no-one has ever legitimately photographed - those who did so illicitly were rapped by the Press Complaints Council - looks set to be repeated with her son, David. Meanwhile, the incredible wealth the books have generated allows Rowling to focus on what remains her primary purposes, her family and her writing.

The final chapter of Harry Potter's saga lies written, locked in a safety deposit box. For the next few years Rowling will work towards reaching that chapter in adventures that will span two more books. The questions remains, what then? There are two things to consider. One is the reaction of children around the globe if the long rumoured climax is true and Harry, as children sometimes do, actually dies. The collective sadness of an entire generation would be palpable and who could judge the consequences of an authorial execution? It is this which spurs fans confidence that she will stay her hand, entwining Harry instead in a romantic ending with Hermione.

Whichever veil she chooses to draw over her multi-book saga, readers will never forget the boy with the lightning-bolt scar. This, in turn, will cast a long shadow over any adult books that flow from her pen. One challenge will be whether she can resist the temptation to return to the ivy draped cloisters of Hogwarts or to trace Harry's adult adventures. Whether her success will be replicated in the world of adult fiction, something she has expressed an interest in trying when she has finished the Potter canon, remains to be seen.

The ultimate legacy of JK Rowling is to create a character that will be read long after she is gone and will sit in the same company as Bilbo Baggins, Peter Pan and Alice in Wonderland. An immortal wizard is how Harry Potter will be remembered, one who had the power to charm the world.

Copyright 2003 The Scotsman Publications Ltd.

Original page date 9 July 2007; last updated 9 July 2007.