Dean Stockwell, the former star of Quantum Leap, an Oscar and Emmy nominee whose theater, film, and television career spanned more than 70 years and 200 credits, has died. He was 85 years old. A representative for the family confirmed that the actor died peacefully in the early hours of November 7 at home of natural causes.

Stockwell, who was born in Los Angeles in 1936, rose to prominence while still in high school, appearing in the anti-racism comedy The Boy With Green Hair in 1948 and in the 1950 version of Rudyard Kipling’s Kim opposite Errol Flynn. But he struggled to adjust to adulthood and, after dropping out of university, re-established his film career with a lead role in Compulsion, a 1959 crime film based on the Leopold and Loeb murder case for which he won a best actor award at the Cannes film festival alongside co-stars Orson Welles and Bradford Dillman.

In the 1980s, Stockwell was on the verge of changing careers. He got his real estate license in New Mexico, and ran an ad for himself in Variety. Instead, he landed roles in films like Wim Wenders’ Paris, Texas, David Lynch’s Dune and Blue Velvet, Robert Altman’s The Player, and Jonathan Demme’s Married to the Mob, the latter of which earned him an Academy Award nomination for Best Supporting Actor.

He also appeared in Battlestar Galactica, The Twilight Zone, and Captain Planet And The Planeteers, a cult children’s animation show.

He was most known for his role as Admiral “Al” Calavicci, a womanizing, cigar-smoking holographic ally to Scott Bakula’s time-traveling physicist Sam Beckett in the sci-fi series Quantum Leap, which aired for five seasons from 1989 to 1993.

He’d go on to star in programs like The Tony Danza Show, JAG, and the critically acclaimed Battlestar Galactica run in the 2000s.

Stockwell also featured in “A Quality of Mercy,” a memorable 1961 episode of The Twilight Zone in which he plays a double role as American and Japanese lieutenants on opposing sides awaiting slaughter. A pre-Star Trek Leonard Nimoy also appeared in the episode.

Several people have used social media to pay their respects to the late actor.

Scott Bakula, who played Sam Beckett, stated he “loved him dearly” and “immediately” bonded with him at his audition for Quantum Leap in 1988.

“My life were changed that day in Brandon Tartikoff’s office. How lucky were we to get him?” he continued.

“A few months later he would be nominated for an Academy Award for his role in Married to the Mob, but he was stuck with us. Serendipity? All I know is, he never tried to get out or complain, he loved the role and the show and the rest was history.

“He became a dear friend and a mentor and we grew very close over the next five, very intense years. Dean was such a passionate man…about life, his work, his art (he was an amazing artist!), his family, all kinds of causes, people, music, the planet, cigars, golf, and on and on!

“Having been a famous child actor, he had a soft spot for every young actor who came on our set. He was very protective of their rights and safety and always checked in with them to make sure that they were ok. His big hearted response to the kids made all of us take notice and be better guardians ourselves.”

He added: “I was honored to know him. He made me a better human being.”

Actor Lydia Cornell tweeted: “Rest in Peace Dean Stockwell. What an amazing actor. He always had a mischievous glint of humour in his eyes. I was honoured to work with him in the pilot for “Quantum Leap” at @NBCUniversal along with Scott Bakula.”

Stockwell, who retired from acting in 2015, did seek a career shift in recent years, creating art and showing it across the United States under his full name, Robert Dean Stockwell.

Stockwell was married twice: first to actress Millie Perkins from 1960 to 1962, and then to Joy Marchenko from 1981 until 2004. He has two children.

His publicist said: “Dean spent a lifetime yo-yoing back and forth between fame and anonymity. Because of that, when he had a job, he was grateful. He never took the business for granted. He was a rebel, wildly talented and always a breath of fresh air. He loved to act, to laugh, smoke cigars and play golf.”