Leonardo DiCaprio Almost Lost Iconic 'Titanic' Role, James Cameron Reveals Why

James Cameron's "Titanic" almost had a different Jack Dawson actor.

Leonardo DiCaprio achieved international stardom after playing the lead role in "Titanic" opposite Kate Winslet. He reportedly charmed everyone — including Cameron — when he auditioned for the 1997 epic romance. In fact, even random staff who were not directly working on the film found their way into the room just to see him.

But while fans may not be able to imagine anyone but DiCaprio playing the poor artist who charmed 17-year-old aristocrat Rose (Winslet), Cameron said in a new interview with Deadline that the Oscar winner was not the studio's first choice for Jack.

While looking back on the casting process of the blockbuster hit, Cameron revealed that he "had to fight" for DiCaprio.

"So I look back and I see — I'm constantly struck by how fragile the whole thing is, how many places it could have failed and blown up along the line, you know? And I think about that casting, Leonardo and Kate in 'Titanic.' Leo, the studio didn't want him; I had to fight for him. Kate really liked him," the filmmaker told the outlet.

But DiCaprio then decided he did not want to audition for the role, so Cameron had to "talk him into it."

The director said he could not imagine the film — which went on to become the highest-grossing movie of all time in 1998 — moving forward without DiCaprio or Winslet.

"So there's a fragility to the whole process, there's a fragility to success. You change one element and it doesn't work," he told Deadline.

DiCaprio reportedly initially did not want to star in "Titanic" as he never wanted to be seen as a "heartthrob."

"Titanic" executive producer Rae Sanchini told E! News that the most difficult part of signing DiCaprio for the role "was convincing him that there was complexity in Jack Dawson."

She explained that DiCaprio had "always played very complicated characters who have very deep flaws" but that Jack "almost seemed, I think when he first looked at it, too easy."

The producer said she believes DiCaprio finally agreed to take on the role because he realized that "playing a character like Jack, who doesn't have any obvious stuff to hide behind...was a challenge in and of itself."

"Titanic" became the first movie to gross over $1 billion worldwide in 1998. With an initial worldwide gross of over $1.84 billion, it held the record for the highest-grossing film of all time for over a decade until Cameron's "Avatar" broke its record in 2010.