EXCLUSIVE: Angela Cartwright, Nicholas Hammond and Kym Karath are remembering their on-screen father Christopher Plummer.

The legendary actor, who famously played Captain von Trapp in the 1965 musical "The Sound of Music," passed away on Friday at age 91, his family confirmed. His wife Elaine Taylor was by his side.

Cartwright and Hammond played von Trapp children Brigitta and Friedrich in the beloved film. Karath also appeared as sibling Gretl von Trapp.

"Christopher Plummer showed this 14-year-old aspiring actor what acting really was," Hammond told Fox News. "Uncompromising in his search for the truth in any role, from Hamlet to Lear to Tolstoy. His re-invention of the role of Captain von Trapp gave the film a gravitas and integrity the stage musical had never had."

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"He made every film and every play he did better by his presence and craft," the 70-year-old shared. "I idolized him as my film father, he was my role model for the years that followed. It is a huge blow to those of us in the 'Sound of Music' family, we, along with the whole world, will miss him very much."

The actors playing members of the von Trapp family in a promotional portrait for 'The Sound Of Music', directed by Robert Wise, 1965. Left to right: Nicholas Hammond as Friedrich, Kym Karath as Gretl, Angela Cartwright as Brigitta, Julie Andrews as Maria, Christopher Plummer as Captain von Trapp, Charmian Carr as Liesl, Heather Menzies as Louisa, Debbie Turner as Marta and Duane Chase as Kurt. (Photo by Silver Screen Collection/Getty Images)

"I was very sad to hear about Christopher Plummer's passing," Cartwright also told Fox News. "'The Sound of Music' cast has always felt like family, so losing Christopher is difficult. He was so very talented and brought such originality and edge to the roles he played. He had a long 91 years... but his legacy will live on forever.  So long, farewell Captain."

"I am deeply saddened by the loss of Chris Plummer," shared Karath. "He was a lovely, brilliantly talented, and incredibly witty man. He was the best of film fathers and a friend. He will be missed by so many."

Plummer spent over 50 years in the entertainment industry, both onstage and onscreen. His most recognized role was perhaps playing the dashing Captain von Trapp in Robert Wise’s "The Sound of Music" opposite Julie Andrews.

The role catapulted Plummer to stardom, but he never took to leading men parts, despite his silver hair, good looks and ever-so-slight English accent. He preferred character parts, considering them more meaty.

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Plummer had a remarkable film renaissance late in life, which began with his acclaimed performance as Mike Wallace in Michael Mann’s 1999 film "The Insider" and continued in films such 2001’s "A Beautiful Mind" and 2009′s "The Last Station," in which he played a deteriorating Tolstoy and was nominated for an Oscar.

Angela Cartwright with her 'Sound of Music' co-star Christopher Plummer. (Photo courtesy of Angela Cartwright)

His other roles ranged from "The Girl With the Dragon Tattoo" to the voice of the villain in 2009′s "Up" and as a canny lawyer in Broadway’s "Inherit the Wind."

In 2012, Plummer won a supporting actor Oscar for his role in "Beginners" as Hal Fields, a museum director who becomes openly gay after his wife of 44 years dies. His loving, final relationship becomes an inspiration for his son, who struggles with his father’s death and how to find intimacy in a new relationship.

"Too many people in the world are unhappy with their lot. And then they retire and they become vegetables. I think retirement in any profession is death, so I’m determined to keep crackin’," he told The Associated Press in 2011.

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Actress Julie Andrews and Christopher Plummer in a scene from the movie 'The Sound of Music.' (Photo by Donaldson Collection/Getty Images)

On Friday, Andrews, 85, revealed how she will never forget her co-star and pal.

"The world has lost a consummate actor today and I have lost a cherished friend," said Andrews in a statement sent to Fox News. "I treasure the memories of our work together and all the humor and fun we shared through the years."

"My heart and condolences go out to his lovely wife Elaine, and his daughter Amanda," she added.

Back in 2018, Cartwright told Fox News that during her time filming "The Sound of Music," Plummer always remained in character, even when cameras stopped rolling.

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"All the kids were a little wary," she recalled at the time. "I always really liked Chris, though. He was very sweet to me"

"Some of the kids didn’t have acting experience, so they weren’t sure what to expect," she shared. "But you gotta admit, he was so lovable in that film, even though he’s very brisk and stern, I think. Now that I look at the movie as an adult, I can appreciate his acting style… And remember, this was a serious actor who’s done Shakespeare. I knew he had a lot of fear that this movie was going to be schmaltzy. And I think it’s that aim to not make this movie so sweet that really made it so popular."

Fox News’ Melissa Roberto and The Associated Press contributed to this report