
John Lithgow is officially joining the Harry Potter HBO series, and the addition of the Conclave star means the new show is breaking a major franchise rule.
Lithgow’s casting in the upcoming Harry Potter series was reported as a rumor earlier this month, but the actor confirmed it himself on February 25.
“Well, it came as a total surprise to me,” he told ScreenRant. “I just got the phone call up at the Sundance Film Festival for yet another film, and it was not an easy decision because it’s going to define me for the last chapter of my life, I’m afraid.
“But I’m very excited. Some wonderful people are turning their attention back to Harry Potter. That’s why it’s been such a hard decision. I’ll be about 87 years old at the wrap party, but I’ve said yes.”
John Lithgow breaks Harry Potter British casting trend
Responses to the Lithgow announcement have been mixed online, with many wondering if the actor knows the controversial background of the IP he’s signed up for.
But regardless, his casting signals a huge change for the franchise, since he’s American.

Historically, the Harry Potter movie cast has always consisted of British stars, both famous and unknown. Dumbledore has only been played by British actors, with Richard Harris, Michael Gambon, Jude Law, and Toby Regbo all playing the role in the past.
There have only been a small number of American actors in the franchise previously, and only in minor roles. Eleanor Columbus (Chris Columbus’ daughter), Verne Troyer, and Julianne Hough all appeared in the original movies.
Columbus himself also recalled from developing the first movie [via The Telegraph]: “Jo Rowling and myself said to each other when we first met, ‘Look, we want this cast to be 100 percent British.’ And by the way, I stuck to that.”
The Fantastic Beasts movie series opened this up slightly, with Johnny Depp, Ezra Miller, Zoë Kravitz, and Dan Fogler all playing major roles. (It does, however, take place in New York.)
Lithgow joining the cast in such a large capacity is a huge hint that the HBO series could be shaking things up for the franchise.
For more, find out what’s going on with the Harry Potter and the Cursed Child movie. You can also find out how many pages are in all the Harry Potter books, and find out what other new TV shows are on the way.