Seven volumes have been translated into 79 languages

Harry Potter turns 20 on Monday when muggle readers in gowns and glasses from Indonesia to Uruguay were set to celebrate the birth of a global publishing phenomenon in 1997.

Harry Potter and the Philosopher’s Stone (later renamed Sorcerer’s Stone for the U.S. market) introduced the boy wizard and a magical cast of supporting characters.

Penniless single mother J.K. Rowling finally succeeded after a series of rebuffs from publishers, and the book became the first instalment of a seven-novel series that has sold 450 million copies worldwide and spawned eight blockbuster films.

The Potter universe now encompasses theme parks in the U.S. and Japan and a permanent exhibition at London’s Warner Bros Studios, helping to turn Ms. Rowling into a billionaire.

No other children’s book has achieved quite as much in terms of both commercial and cultural impact, turning an entire generation of boys and girls into enthusiastic readers who would happily join midnight queues at bookshops as each novel came out.

Narrative verve

If some of the early reviews took issue with Ms. Rowling’s pedestrian writing and bald characterisation, everyone agreed about the narrative verve on show in the Philosopher’s Stone, starting with the delivery of a letter that will, like alchemy, transform the 11-year-old hero’s life forever.

“Once you start reading it, you enter a magical world, a world where you could be special, a world with clever things, with the idea that it all just might exist,” Durham University education professor Martin Richardson said. “The characters become part of the family. It starts to enter the nation’s DNA,” he said.

Far beyond Britain and English-language markets, the saga wove itself into the world’s literary DNA.

The seven volumes have been translated into 79 languages in 200 countries, and Monday’s 20th anniversary would feature fancy-dress reading parties around the world, starting in Australia and ending in Canada and the U.S. West Coast, at libraries, bookshops and British embassies.