Kit Harington cast as Gilderoy Lockhart in Harry Potter season two

Harry Potter casting takes another unexpected turn

Hoult was only announced as the new Defence Against the Dark Arts teacher on 11 August, with the actor expected to begin filming when production got underway this autumn. However, scheduling issues have forced him to step away, with Harington confirmed as his replacement on Monday.

The Game of Thrones star is already surprisingly familiar with Lockhart, having provided the character’s voice for Audible’s full-cast version of Harry Potter and the Chamber of Secrets late last year.

Harington previously told Variety that agreeing to voice Lockhart in the audiobook was an easy decision because he loves the character.

"As far as cameos in a series go, you don’t get much more entertaining and fun to do as an actor than Gilderoy Lockhart. It was a no-brainer."

– Kit Harington, speaking to Variety in December about voicing Lockhart

His move into the HBO series also reunites him with the network, having previously worked with the company on Gunpowder and Industry.

What happens next

The first season of HBO’s Harry Potter series is due to arrive on Christmas Day, with Harry Potter and the Philosopher’s Stone set to premiere on HBO and HBO Max on 25 December.

The new trio will be led by Dominic McLaughlin as Harry Potter, Arabella Stanton as Hermione Granger and Alastair Stout as Ron Weasley.

HBO has already given the series a head start on its second chapter, with season two renewed ahead of the first season’s release.

There has also been a change behind the scenes, with Jon Brown stepping up to co-showrunner alongside Francesca Gardiner for the second season.

Brown previously worked as a writer on the first season, with Gardiner remaining in charge as the series continues its planned journey through the original books.