Actor Michael Gambon dies 0:36

(CNN) -- Daniel Radcliffe, the protagonist of the original "Harry Potter" film franchise, remembers his late co-star Michael Gambon after he passed away from pneumonia this week at age 82.

"I am very sorry to learn of the passing of Michael Gambon. He was, on and off camera, a legend," Radcliffe wrote on his verified Instagram on Thursday, along with a touching video montage showing Gambon playing Hogwarts headmaster Dumbledore in the "Harry Potter" films.

Radcliffe also included a quote from Dumbledore in his caption: "Happiness can be found even in the darkest moments, if one only remembers to turn on the light."

Rupert Grint, who played Ron Weasley in the film series, also posted a tribute to Gambon on Instagram, writing: "So sad to hear about Michael. He brought a lot of warmth and mischief to every day on set. He captivated me as a child and became a personal role model for me in terms of finding fun and eccentricities in life."

Michael Gambon and Daniel Radcliffe in "Harry Potter and the Half-Blood Prince". Warner Bros./Alamy Stock Photo

Gambon played Dumbledore in six of the eight "Harry Potter" films, a role he assumed after Richard Harris' death in 2002.

advertising

"Harry Potter" author J.K. Rowling also took some time to remember the actor on Thursday, writing on X/Twitter: "Just heard the terrible news about Michael Gambon. The first time I saw him was in King Lear, in 1982, and if you had told me that this brilliant actor would appear in anything I had written, I would have thought you were crazy."

"Michael was a wonderful man, as well as an exceptional actor, and I loved working with him."

Actor Jason Isaacs, who played Lucius Malfoy in the "Potter" films, called Gambon "magnificent" in his X/Twitter tribute and continued, "I learned what Michael's performance in The Singing Detective could be: complex, vulnerable and fully human. The biggest thrill of being in the Potter films was that he knew my name and shared with me his fearless and gritty sense of fun."

Gambon died at age 82 after a "bout of pneumonia," according to a statement issued on behalf of his family on Thursday, PA Media reported.

"We are devastated to announce the loss of Sir Michael Gambon," read the statement issued by his manager Clair Dobbs, according to PA.

Daniel RadcliffeHarry Potter