British actor Kit Harington, best known for his role as Jon Snow in "Game of Thrones," has joined the cast of HBO's upcoming "Harry Potter" series as Gilderoy Lockhart for its second season.

Harington is taking over the role after Nicolas Hoult, who was previously announced to play Lockhart, left the project due to scheduling conflicts, according to a post by HBO Max on social media.

A prominent character in J.K. Rowling's "Harry Potter and the Chamber of Secrets," Lockhart teaches Defense Against the Dark Arts at Hogwarts and presents himself as a celebrated wizard. In reality, however, he takes credit for other wizards' achievements.

Lockhart was previously portrayed by Kenneth Branagh in the 2002 film adaptation of "Harry Potter and the Chamber of Secrets."

Based on Rowling's seven-book series, the HBO production will retell the story with a new cast. The eight-episode first season, based on "Harry Potter and the Philosopher's Stone," is set to premiere Dec. 25.

The series will star Dominic McLaughlin as Harry Potter, Arabella Stanton as Hermione Granger and Alastair Stout as Ron Weasley.