Inside the Magical World of 'Harry Potter' Author

July 15, 2009— -- The heart-pounding, often harrowing tales of a young wizard and his friends battling the forces of evil have introduced a generation to reading. And with more than 400 million copies of the "Harry Potter" books sold around the world and earnings for the first five movies reaching $4 billion, Harry Potter has become a multi-billion dollar brand.

But before becoming a worldwide phenomenon, Harry Potter existed only in the mind of Joanne, better known to the world as author J.K. Rowling, who was a struggling, out-of-work single mom when she decided one day to write a book.

Though the series has taken her 17 years to write, when Rowling began putting words to paper, it was magic.

Watch "J.K. Rowling: A Year in the Life," Thursday, July 16 at 8 p.m. ET on ABC.

An epic saga of childhood confusion, danger and adventure, Harry Potter is more than just a children's story. Behind the witchcraft and the wizardry lie an intensely moral fable about good and evil, love and hatred, life and death. Yet Rowling, a slender, down-to-earth woman, still seems surprised at her success.

Like her orphaned hero, Joanne Rowling was brought up on suburban British streets like the one the Dursleys live on, in the books, in the south of England, outside Bristol. Her house even had a cupboard under the stairs; but unlike Potter, Rowling didn't have to sleep there.

Rowling and Potter share the same birthday -- July 31 -- and Rowling, with her sister Di, endured similar childhood traumas and massive disappointments, as the novels' protagonist.

At the impressionable age of nine, Rowling's family moved from the suburbs to the country, near the Forest of Dean -- a location that offered a range of imaginative possibilities: magical creatures, mystery and intrigue for Rowling.

"I'm very drawn to, to a forest and it's my favorite part of the Hogwarts grounds," Rowling said in a November 2006 interview with James Runcie, which has been obtained by ABC News. "The advantage of a forest is it can be so many things: it can be a place of enchantment, you never imagine a crowd in a forest, it's a solitary place. But there's just something, is it because it used to be a place of shelter and safety to us I suppose, so I think, I, I am very drawn to them, even though they can be spooky."

Mother's Illness Tests Rowling

Rowling delved into writing at an early age, but her thoughts about love, death, heaven and hell were tested when her mother was diagnosed with multiple sclerosis in 1980.

"She had a very virulent form of the illness and at that time there were no drug treatments at all," Rowling said. "And they said 'well you've got multiple sclerosis, see you.'"

The illness devastated Rowling and her sister, and strained her relationship with her father.

"I was very frightened of my father for a very long time," she said in the 2006 interview. "...I also tried desperately to get his approval and make him happy, I suppose, and then there came a point quite shamingly late in life where I couldn't do that anymore, and so, I haven't had any contact with my father now for a few years."

Rowling's far from ideal relationship with her father inspired idealized father figures, like Hagrid, Dumbledore, and Sirius Black, in the series. She says the absence of any meaningful relationship with her father and the loss of her mother have been the two of the most important influences on her writing.

"I had been writing for six months before she died and, the weird thing is, the essential plot didn't change after my mother died, but everything deepened and darkened," Rowling said. "Harry was always going to lose his parents. And it was always going to be a quest really to avenge them, but to avenge everyone against this, this creature -- this being who believes that he can make himself immortal by killing other people. So that's, that that's something I'd created before she died, but yes, its seeped into every part of the books. I think, in retrospect now I've finished I see just how much it informed everything."

After her mother's death, Rowling moved to Portugal to teach English as a foreign language. There, she married television journalist Jorge Arantes, with whom she had daughter, Jessica. But the marriage failed after two years and Rowling succumbed to depression.

"I had had a short and really quite catastrophic marriage and I'm left with this baby and I've got to get this baby back to Britain and I've got to rebuild us a life," Rowling recalled. "...Adrenalin kept me going through that and it was only when I came to rest that it hit me what a complete mess I had made of my life and that hit me quite hard."

Her deep depression inspired the creation of dementors, "the foulest creatures that walk this earth," who prey on people's happiness and suck out their souls in the Harry Potter series.

"I was definitely clinically depressed. And that's just characterized for me by, a numbness, just a sort of coldness and an inability to believe that you will feel happy again or that you could feel light-hearted again," she said. "It's just all the color drained out of life really."

'Potter' Series' Moral Dilemmas Play Out in Life

The "Harry Potter" books may be located in an alternative fantasy world, but they address serious moral questions about the nature of trust, loyalty, integrity -- and the need to make a stand against evil.

Through the series, Harry Potter has to learn what it means to be a force for good against the dark arts of Lord Voldemort.

"I think we all understand what an act of evil is and Voldemort qualifies extravagantly for acts of evil," Rowling explained. "He has killed not out of self-defense, not to protect, not to do, not for any of the reasons that we might all be able to envisage. Most of could envisage ourselves killing in certain extreme situations if people we loved were threatened, or in war. He's killed cold-bloodedly, sometimes for enjoyment and for his own personal gain."

In November 2006, Rowling locked herself in the Balmoral Hotel in Edinburgh to work on the crucial final chapters of "Harry Potter and the Deathly Hallows" -- the final Harry Potter book. As the most anticipated new book of this century neared completion, it marked the end of a personal project for Rowling, who had been immersed in the magical world of Potter and her characters for seventeen years. With its completion, Rowling says it's time to focus on her family and her own well-being.

"I am happier now than I have ever been in my life, I am happier now than I was as a child, teenager, young adult and I think middle age is probably going to be my time," she said.

Watch "J.K. Rowling: A Year in the Life," Thursday, July 16 at 8 p.m. ET on ABC.