Kirk Douglas, one of the last great stars of Hollywood's golden era, turned 100 on Friday

Spartacus is now a centurion.

Kirk Douglas, one of the last great stars of Hollywood’s golden era, turned 100 on Friday. Born during the height of World War I to poor, illiterate Russian immigrants living in upstate New York, the legendary actor pulled himself out of poverty to become one of the most famous men in the world.

“My parents came from Russia and my original name was Izzy Danielovitch,” Douglas told PEOPLE in 2015. He changed his name, unwieldy and too Semitic for Hollywood at the time, to Kirk Douglas before pursuing a career in show business. “I wish I had kept it,” he said, looking back on the decision. “It’s more interesting to keep your original name. But can you imagine that name on a marquee?”

At the time, aesthetics were not the only reason Douglas was eager to part with the family name. His father, who scraped a living reselling rags and scraps of metal, was never emotionally supportive. “My father was not very affectionate,” Douglas told PEOPLE. “He was never interested in what I was doing. I had six sisters and no brothers and I wanted to be close to my father and he just ignored me.”

Credit: Alberto E. Rodriguez/Getty Images

Although close with his mother, Douglas developed a chip on his shoulder that, at first, he channeled into athletics. “I was always in pretty good shape. In college I was a wrestler and I made money in the summer working at a carnival,” he remembered. “I was the guy who was a plant, the mark, and I’d wrestle people in the audience.”

With no money to pay tuition, Douglas talked his way into the dean’s office at St. Lawrence University and ended up convincing the school to give him a loan, which he paid off working as a university janitor and gardener. He joined the Navy not long after the U.S. entered World War II, and served until he was medically discharged for war injuries in 1944.

Douglas’ big break came after the war, when his friend and fellow aspiring Jewish actor Lauren Bacall recommended him for a role opposite Barbara Stanwyck in 1946’s The Strange Love of Martha Ivers. “I met Betty in drama school,” Douglas said of Bacall. “I was just coming out of the Navy and she was already in Hollywood. We met at a restaurant and she had her script of To Have and Have Not with her and she read me some of her lines, the whistle scene. I thought, she is going to be a star.”

The two also had a brief fling, and Bacall did what she could to help Douglas stay on his feet. “I had a thin coat in the winter and we were talking,” he remembered. “That night, she talked her uncle out of his overcoat … and I wore it for two years.”

Douglas married another young actress, and mutual friend of Bacall’s, Diana Dill, before he was discharged from the Navy in 1943. They had two sons, Michael in 1944 and Joel in 1947, before they divorced in 1951. But even to this day, the two keep in touch. “She’s a good friend of my wife!” Douglas said of his current wife, Anne. “They have lunch together. Anne calls her ‘our first wife.’ ”

Kirk Douglas and Anne Douglas in 1954.
| Credit: Courtesy Kirk and Anne Douglas Private Collection
Kirk Douglas and Anne Douglas in 2008.
| Credit: Valerie Macon/AFP/Getty Images

Douglas cemented his onscreen tough-guy status while receiving his first major critical praise for 1949’s Champion. He took a gamble on the part, turning down a bigger-budget project for the film, which earned him his first Academy Award nomination. The decision to follow his gut and take less money for a better part made a major impact on his career. In 1955, Douglas trusted his instincts again and alienated himself from the Hollywood studio system by forming his own production company, which he named Bryna Productions after his mother.

With celebrated roles in films like Along the Great Divide (1951), Detective Story (1951) and The Bad and the Beautiful (1952), Douglas became one of Hollywood’s biggest box-office stars throughout the ’50s and ’60s. But even at the height of his success, he never lost his independent, outsider spirit. After breaking his contract with Warner Bros. to form his own production company, Douglas starred in and produced films like the Stanley Kubrick-directed, anti-war Paths of Glory (1957) and the blacklisted, Dalton Trumbo-written Spartacus, also directed by Kubrick.

Douglas’s decision to once again defy conventions and work with a blacklisted writer helped to end the communist purge in Hollywood. “Dalton Trumbo was one of the best writers we had. He was on the Hollywood blacklist, so he was working under another name,” Douglas told PEOPLE. “It was such a terrible, shameful time. So I decided the hell with it! I’m going to put his name on it. I think that’s the thing I’m most proud of because it broke the blacklist. It caused me a lot of trouble, but it was worth it.”

Douglas remarried in 1954 to producer Anne Buydens. He met the Belgian-born beauty in Paris while filming Lust for Life. They had two sons, producer Peter Douglas and actor Eric Douglas, who died of a drug overdose in 2004. “When you take inventory about all the moments of your life … you don’t forget the sad moments,” Douglas said of Eric’s death. “And in many ways, they mean more than the happy moments. Eric’s passing is a big sadness in my life. And I’ve had lots of sad moments.”

During a career that spanned seven decades, Douglas earned three Oscar nominations, two Golden Globes and made over 90 films. His philanthropic work is perhaps even more impressive. The actor has established over 400 playground parks for children across Los Angeles, funded minority scholarships at major universities, donated over $40 million to the Motion Picture and Television fund alone, and recently donated a robot to the Children’s Hospital of Los Angeles — aptly named Spartacus. But of all his many accomplishments, Douglas is most proud of being a dad, especially in light of his own strained relationship with his father.

(L-R) Joel Douglas, Peter Douglas, Kirk Douglas, Michael Douglas and Eric Douglas in 1988.
| Credit: Richard Corkery/NY Daily News Archive/Getty Images

“I’m much more demonstrative with my kids about hugging and kissing them and telling them that I love them. My father wasn’t like that,” he admitted. Still, Douglas’ relationship with his kids has not always been perfect, and he recognized the sometimes-negative role his success played in their lives. “My boys didn’t have my advantages,” he explained. “When you are so poor as I was, and when you start at the bottom, you are driven to succeed. They grew up privileged and it was harder for them to be driven.”

His relationship with his son Michael, whom he called “the hardest to know” of his children, has long been a work in progress. “Michael was always more distant of all my sons, and I always wondered why,” he said. “When I asked him if I was a good father, he answered me with one word, ‘Ultimately.’ ”

Kirk Douglas (L) and Michael Douglas.
| Credit: Lisa Larsen//Time Life Pictures/Getty

But time has healed many wounds, and now Douglas says his oldest son calls “every Sunday, if not more.” He’s also close with his grandchildren, some of whom he fears might one day go into the family business. “They are fantastic kids. Carys plays the piano and loves to dance and is a wonderful poet. Dylan plays the lead in all the school plays,” he said of Michael’s two children with Catherine Zeta-Jones. “I think he’ll be an actor and maybe Carys, too. I think my family is doomed!” In all, Douglas now has seven grandchildren. “I’ve loved watching all my grandchildren grow up,” he added.

Kirk Douglas (L) and Michael Douglas in 2003.
| Credit: Kevin Winter/Getty

Speaking about his dad at a recent MPTF gala, Michael said of his dad’s birthday, “It’s an amazing personal century, filled with so many accomplishments and achievements that, if I recounted them all, we’d still be here for Kirk’s 105th birthday. My dad is an icon. He’s a legend. He’s a true movie star from an era when movie stars were looked at as our version of royalty, and Kirk earned that status.”