JK Rowling had one strict rule for any kid wanting to play her wizard when casting for the movies began almost 25 years ago.

They had to be “100 per cent British,” she said. No Americans allowed.

London-born Daniel Radcliffe, whose movie career was henceforward guaranteed, was just 10 years old when he was cast in the first of eight films, Harry Potter and the Philosopher’s Stone in 2001.

“To get the part I sent in this application and a photo of myself to the Newsround television program. I waited weeks and months, and nothing happened,” he told the Golden Globes website in 2022.

“I sent them a video of myself, dressed up as my drama teacher, who was a girl, so that was pretty scary. I did this rap song about how much I wanted to be in the film.

“I was actually in the bath at the time the call came … my dad came up and told me that I did get it, and I just started to cry I was so happy.”

Rupert Grint was 11 when he was cast as Ron Weasley – Harry’s awkward best friend at Hogwarts – while Emma Watson was just 10 when cast as the brilliant and wise student, Hermione Granger.

Fast forward to 2024, a year after Warner Bros Discovery announced a Harry Potter TV series, the official Harry Potter Instagram account published a UK open casting call for the reboot.

Children aged 9 to 11 as of April next year and “residents of the UK or Ireland” are invited to audition for the roles of Harry Potter, Hermione Granger and Ron Weasley.

“We are committed to inclusive, diverse casting. For every role, please submit qualified performers, without regard to ethnicity, sex, disability, race, sexual orientation, gender identity, or any other basis protected by law unless otherwise specifically indicated.”

Rowling, known for controversial comments on transgender issues, said in a statement at the time she would be involved in the series.

“[Formally HBO Max] Max’s commitment to preserving the integrity of my books is important to me, and I’m looking forward to being part of this new adaptation which will allow for a degree of depth and detail only afforded by a long-form television series,” she said.

Colour-blind casting

The child actors have been asked to provide two video tapes for the audition.

One video must be “a short poem or story” (though nothing from Harry Potter) and the second “telling us a bit about yourself, including your date of birth, height and where you live”.

It also asks for children to use their own accents.

JKR, who maintains creative control over the franchise and has been confirmed as executive producer on the TV series, has previously given some insights on what the trio look like.

For a 2015 London  theatre production of Harry Potter and the Cursed Child, black actor Noma Dumezweni plays the fictional witch Hermione.

“Canon: Brown eyes, frizzy hair and very clever … white skin was never specified. Rowling loves black Hermione,” she wrote on Twitter (now X) at the time.

She later told The Guardian that “Noma was chosen because she was the best actress for the job”.

“I had a bunch of racists telling me that because Hermione ‘turned white’ – that is, lost colour from her face after a shock – that she must be a white woman, which I have a great deal of difficulty with.

“But I decided not to get too agitated about it and simply state quite firmly that Hermione can be a black woman with my absolute blessing and enthusiasm.”

Ncuti Gatwa is the 15th Doctor and Millie Gibson plays companion Ruby Sunday. Photo: Disney+

The lead role in the 2019 comedy drama, The Personal History of David Copperfield, was played by UK-born Dev Patel, whose parents are Indian.

The 15th Dr Who was Ncuti Gatwa, the first black actor, first African-born actor and first openly queer actor to headline as the Doctor.

Bridgerton, a period drama based on Julia Quinn’s bestselling 2000 novel series that chronicles the romances of the Bridgerton family in Regency-era London, has an ensemble that spans a wide variety of ethnicities and races.

“I’m ashamed to say that the word ‘inclusive’ only started to be used a few years ago in our business,” UK agent for the series, Kelly Valentine Hendry, told British Vogue.

“It was a world of white men making content through their own lenses.

“It wasn’t until recently that I felt confident enough to challenge the people I answer to,” she said in a cover story about colour-blind period dramas becoming the norm in Hollywood.”

Rupert Grint, Emma Watson and Daniel Radcliffe became household names, thanks to Harry Potter. Photo: Getty

Meanwhile, the Harry Potter TV series will see each season based on one of the seven books.