Alan Rickman was frustrated with his character Severus Snape from the Harry Potter films, reveal letters from the actor’s personal collection that will be up for auction in London, the Independent reported.

Rickman died of pancreatic cancer in 2016. He had a wide-ranging career on the British stage and played numerous well-regarded characters in films – including Die Hard (1988), Robin Hood: Prince of Thieves (1991) and Sense and Sensibility (1995), but it was his role as Severus Snape, the caustic yet caring wizard from the Harry Potter movies based on JK Rowling’s bestsellers, that made him a global name.

However, Rickman had doubts about his character and the films, the letters reveal. One missive from David Heyman, the producer of the fantasy movies, refers to the second entry in the franchise, Harry Potter and the Chamber of Secrets (2002): “Thank you for making HP2 a success. I know, at times, you are frustrated but please know that you are an integral part of the films. And you are brilliant.”

While working on The Half-Blood Prince (2009), Rickman wrote a note titled “Inside Snape’s Head”, in which he complained about the movie’s director: “It’s as if David Yates has decided that this is not important in the scheme of things i.e. teen audience appeal.”

The collection, totalling 35 boxes, includes a letter from JK Rowling, in which she thanks Rickman for “doing justice to my most complex character”, Independent reported. The letters have been valued at £950,000.

“Other items in the collection include letters from the Prince Charles, Bill Clinton and Tony Blair, along with Rickman’s copy of the Die Hard script, the 1988 blockbuster movie in which he played the villain Hans Gruber,” the newspaper reported. Also included are the screenplays of Rickman’s films Truly Madly Deeply and Robin Hood: Prince Of Thieves.

Harry Potter and the Half-Blood Prince (2009).