The following is from the introduction to LIFE’s special tribute issue Harry Potter: The Extraordinary Adventure.

“Debut author and single mother sells children’s book for £100,000.” So announced a July 1997 headline in the Guardian newspaper touting the record-breaking windfall novice writer Joanne Kathleen Rowling earned for Harry Potter and the Philosopher’s Stone. It was the first in a planned series of novels about a powerful young wizard drawn into an epic battle of good versus evil, and the article posited that Harry “could assume the same near-legendary status as Roald Dahl’s Charlie, of chocolate factory fame.”

Nearly two and a half decades later, it’s a safe bet that children are more well-versed in the adventures of Harry and his plucky best mates Ronald Weasley and Hermione Granger than they are with Dahl’s Charlie Bucket. Rowling’s characters have become a part of the global cultural lexicon thanks to the fantasy juggernaut. It seems nearly everyone’s heard of the Boy Who Lived. “The characters were so funny and so very specific, and the world came alive on the page,” says Anne Rouyer, supervising young adult librarian at the New York Public Library. “It was one of those books you could sell to any kid, whether they were [an avid] reader or a reluctant reader. Even now, kids just discover them, and they’re just as magical as they were 25 years ago.”

Looking back, few would have imagined the extent to which that first book’s young protagonist—an English orphan whisked away from a life of drudgery and abuse into a world where staircases move, paintings talk, and owls deliver the mail—would become a dominant force in popular culture the world over.

By the time the novel was released stateside in 1998 as Harry Potter and the Sorcerer’s Stone, it had become as plain as the beard on Dumbledore’s face that there was something special about the passion with which young readers devoured the 300-plus-page novel. Suddenly, everyone under the age of 12 knew the story of how the dark wizard Lord Voldemort murdered Harry’s parents, leaving the infant alive but with a prominent scar in the shape of a lightning bolt on his forehead. Words like Muggle and Quidditch became common parlance, and—gasp!—reading was suddenly cool.

“As a public librarian and a literacy advocate, what I found most amazing about the whole phenomenon was how Harry Potter encouraged younger kids to read ‘up’ in terms of their age group,” says Jack Martin, executive director of the Providence Public Library in Rhode Island. “You had four- and five-year-olds wanting to read these books that were geared to [older] kids … Everybody wanted to be a part of that universe.”

For that first generation who discovered Harry’s adventures, the story felt “fresh and new,” according to Dr. Frankie Condon, associate professor of English at the University of Waterloo in Ontario, Canada, where she teaches a class titled Popular Potter. “Rowling created a coterie of characters who spoke in a very modern way to a new generation of children contending with new ideas about difference … There’s just tremendous skill in the crafting of the books that you have to be impressed with.”

Not surprisingly, Hollywood came calling. The first movie adaptation, released in 2001, earned upward of $1 billion at the global box office, transforming actors Daniel Radcliffe, Rupert Grint, and Emma Watson—who played Harry, Ron, and Hermione, respectively—from young unknowns into tween superstars. The subsequent films were similarly successful: The saga’s finale, Harry Potter and the Deathly Hallows—Part 2, which brought the series to an epic conclusion in 2011, boasted ticket sales totaling $1.3 billion worldwide.

Not everyone was enthralled, however. As the franchise continued to grip the public imagination, some conservative religious groups took issue with children reading stories that they felt glorified the occult; the American Library Association found that from 2000 to 2009, the Harry Potter novels ranked near the top of their list of titles that some found objectionable. But just as earlier attempts to ban comic books, heavy metal music, and video games had failed to sway young fans, the efforts to quash enthusiasm for Harry Potter generally met with little success.

Parodies and homages of all kinds proliferated. On TV, shows like Saturday Night Live, The Office, and
The Simpsons all got in on the act. Colleges founded leagues devoted to the wizarding sport of Quidditch, though the game had to be modified given that players didn’t have the magical luxury of chasing one another
on flying broomsticks. Musicians introduced “wizard rock,” a genre of quirky novelty songs inspired by the books. The group Harry and the Potters would routinely draw hundreds of spectators to their New York Public Library sets, where they performed such songs as “My Teacher is a Werewolf” and “Save Ginny Weasley.”

The founding members of the band also helped launch the Harry Potter Alliance with fellow aficionado Andrew Slack in 2005. The organization, which recently changed its name to Fandom Forward, was created with a mission to do good works in the world. “The books have helped to raise a very progressive generation of young people,” Condon says. “They teach young people to be wary of the violent exercise of power, not only over people’s bodies, but also over people’s minds. And they teach young people that the seeds of what we most despise and oppose are inside us, too.”

Yet the sterling reputation of the beloved franchise has been tarnished of late by none other than Rowling herself. In 2019, the author began to trumpet her support for a British tax expert fired from her job at a think tank over statements she had made on Twitter that some believe are transphobic. Rowling subsequently published a 3,600-word essay titled “J. K. Rowling Writes about Her Reasons for Speaking Out on Sex and Gender Issues.” In the piece, she claimed “empathy” for trans people, but she also included talking points often used by those who oppose LGBTQ+ rights. For many, it’s a perplexing turn of events—after all, in Harry Potter and the Goblet of Fire, Dumbledore admonishes: “It matters not what someone is born, but what they grow to be!”

“I can’t explain that or justify it,” Condon says. “I can say that it threatens the legacy of the books. Of course, there’s a long history of writers saying and doing terrible things, even as they produce what have been received as great works of art. In this case, these are young people who this writer helped to raise up who … will have to [decide] whether they can turn the message of the books against the messenger without discarding the books themselves. She’s presented her readers, the people who’ve loved her work the most, with a terrible problem.”

In response, Radcliffe, Grint, and Watson issued strongly worded statements supporting trans women. Other public figures, including author Stephen King, waded into the conversation, too, many eventually coming out against Rowling. Two major fan sites, The Leaky Cauldron and MuggleNet, removed images of the author and announced they will not write about her non-Potter creative endeavors. In December 2021, US Quidditch and Major League Quidditch announced a pending name change in response to Rowling’s “anti-trans positions.”

Still, the author’s controversial statements haven’t diminished the overall health of the larger wizarding industry. Warner Bros. is set to release the third film in the Potter spin-off movie franchise, Fantastic Beasts and Where to Find Them, in April 2022, and performances of the Tony Award–winning play Harry Potter and the Cursed Child have resumed after the COVID-19 pandemic closed theaters in 2020.

Visitors are once again traveling to theme parks in Orlando, Hollywood, Japan, and China to enjoy rides, shops, and treats inspired by the books, and Warner Bros. Studio Tour London—The Making of Harry Potter is attracting fans to the Leavesden soundstages on which the movies were shot. This past summer saw the arrival of Harry Potter New York, billed as “an immersive three-story retail experience” and said to offer the world’s largest collection of Harry Potter and Fantastic Beasts products.

The continued appetite might simply speak to the powerful hold the books and the much-beloved characters retain over the minds of readers who’ve grown up imagining which of Hogwarts’s four houses they might be sorted into. Would they belong to Gryffindor, Hufflepuff, Ravenclaw, or Slytherin? For those fans, the books weren’t just entertainment—they helped them make sense of the world, and of themselves.

“Like many readers, I was drawn to the books because they tapped into my fantasy of being special, but they teach us about the inescapability of the ordinary,” wrote author and editor David Busis in a 2017 New York Times opinion piece. “Ultimately, though, I don’t read J.K. Rowling—or M.T. Anderson, or Ursula K. Le Guin—because of what their books have to tell me about life. I read them because these writers have mastered the ancient magic of storytelling, and because they remind me of what it’s like to be young, living in a world that seems both simple and incomprehensible. Childhood taught us that wonder is our only true defense against the ordinary. We forget that at our peril.”

Here are a selection of photos from LIFE’s special tribute issue Harry Potter: The Extraordinary Adventure.

TCD/Prod.DB/Warner Bros./Alamy

Director Alfonso Cuaron on the set of Harry Potter and the Prisoner of Azkaban, 2004.

© Warner Bros./Courtesy Everett Collection

This behind-the-scenes photo shows the doubles for actors Daniel Radcliffe, Rupert Grint, Emma Watson, Robbie Coltrane on the set of Harry Potter and the Order of the Phoenix, 2007.

© Warner Bros./Courtesy Everett Collection

This first edition of Harry Potter and the Philosopher’s Stone was annotated by author J.K. Rowling.

Will Oliver/AFP/Getty

Dan Fogler (left) and Brontis Jodorowsky appeared in Fantastic Beasts: The Crimes of Grindelwald, another series penned by J.K. Rowling.

© Warner Bros./Courtesy Everett Collection

This sketch by author J.K. Rowling showed the layout of her Hogwarts School of Witchcraft and Wizardry.

Nils Jorgensen/Shutterstock

This bookstore in Arlington, Va., was ready for the rush as Harry Potter and the Goblet of Fire, the fourth book in the series, was about to go on sale in 2000.

Alex Wong/Newsmakers/Getty

Michael Gambon as Dumbledore in Harry Potter and the Goblet of Fire, 2005.

© Warner Bros./Courtesy Everett Collection

Bill Hader played Dumbledore and Kristen Wiig was Minerva in a 2007 skit on Saturday Night Live.

Dana Edelson/NBCU Photo Bank/NBCUniversal via Getty

The franchise’s appeal extended to theme parks, as visitors enjoyed the Wizarding World of Harry Potter attraction at Universal Studios Beijing in 2021.

Kevin Frayer/Getty