A stamp of the Hogwarts Express Sourced by the Telegraph

But there have been controversies, too, often with the casting.

In the latest row, Rowling has had to defend the casting of an Asian actress as Nagini in the latest instalment of the Fantastic Beasts franchise.

The final trailer for Fantastic Beasts: Crimes Of Grindelwald revealed South Korean actress Claudia Kim transforming from a woman into Voldemort’s snake.

Critics argued having an Asian actor play the role of Nagini, who is submissive to Voldemort in the Harry Potter books, was offensive.

One tweeted Rowling: “Listen Joanne, we get it, you didn’t include enough representation when you wrote the books. But suddenly making Nagini into a Korean woman is garbage.”

Rowling replied explaining that Nagini is a Naga, a “snake-like mythical creatures of Indonesian mythology”.

She said: “They are sometimes depicted as winged, sometimes as half-human, half-snake. Indonesia comprises a few hundred ethnic groups, including Javanese, Chinese and Betawi. Have a lovely day.”

Rowling later added she had been hiding the fact that Nagini was a Maledictus — a female who had been turned into an animal due to a blood curse — for 20 years.

She could have added that Nag and Nagina (or Nagaina), the male and female usually of the cobra, are Indian concepts, with the female being much deadlier, of course (see Kipling’s Rikki-Tikki-Tavi).

A Hermione Granger stamp Sourced by the Telegraph

For Harry Potter fans worldwide, Britain’s Royal Mail is issuing a new set of 15 stamps from the eight films about the boy wizard, featuring Harry Potter himself plus Hermione Granger, Ron Weasley, Ginny Weasley and Neville Longbottom.

Also shown are the iconic modes of transport from the movies: the Hogwarts Express; Hagrid’s enchanted motorbike; the flying Ford Anglia and the Knight Bus. The Triwizard Cup also makes an appearance.

Five of the stamps are presented in a miniature sheet and depict the professors: Pomona Sprout; Remus Lupin; Horace Slughorn; Sybill Trelawney and Severus Snape set against a background of the Marauder’s Map.

The stamps include hidden details that are only visible under ultraviolet light. In addition, the style of the ‘1’ depicting the value on each of the stamps, mirrors the font used for the films.

“Book covers from JK Rowling’s novels featured in our stamps in 2009 but this is the first time they are based on the films,” a spokeswoman for Royal Mail told The Telegraph.

Philip Parker, head of “stamp strategy” at Royal Mail, added: “The Harry Potter movies continue to thrill and delight audiences of all ages. The goal with our stamps is to capture the excitement of the wizarding world and the heroism of the students of Hogwarts School of Witchcraft and Wizardry.”

The stamps, designed in collaboration with Warner Bros. Consumer Products, will be released in the UK via 7,000 post offices (rather than owls as in the movies) on October 16. But there is also expected to be heavy demand from collectors and Harry Potter fans and clubs throughout the world.

Royal Mail reminded fans that film audiences were first introduced to Harry Potter and the wizarding world in 2001, with the release of Harry Potter and the Philosopher’s Stone. The eighth film, Harry Potter and the Deathly Hallows — Part 2 (2011), “brought the series to an electrifying conclusion in the battle between the good and evil meet at Hogwarts Castle for an epic showdown”.

It also issued explanatory notes with each of the stamps.

For example, “Hermione is considered by many at Hogwarts to be the brightest witch of her age. On her many adventures with Harry and Ron, it is often thanks to Hermione’s educated mind, grasp of logic and quick thinking that the trio triumphs.”

As for Harry Potter, he learns on his 11th birthday that “he has been accepted to Hogwarts School of Witchcraft and Wizardry. Harry and his friends, Ron and Hermione, brave the challenges of school life while facing the increasing threat of the dark forces led by Lord Voldemort. As Voldemort returns to power, Harry realises that only he can stop the Dark Lord.”

It is now accepted children everywhere took up reading only because of Harry Potter. “More than two decades ago, a young Harry Potter was whisked onto Platform 9¾ at King’s Cross Station, and readers everywhere were swept along with him into a magical universe, created by JK Rowling. In the years since, the seven Harry Potter bestsellers have inspired eight blockbuster movies, an award-winning stage play, and, more recently, the successful start of the Fantastic Beasts five film franchise.”

Harry Potter characters stamp Sourced by the Telegraph