Robert De Niro and Martin Scorsese on Building ‘Love’ and ‘Trust’ During Their 50-Year Friendship (Exclusive)

The actor and director have made 10 feature-length films together, including their most recent collaboration, ‘Killers of the Flower Moon’

Robert De Niro and Martin Scorsese have plenty of mutual admiration.

The actor, 80, and director, 81, enjoy a professional relationship and personal friendship that goes back five decades, and they both express their deep respect for each other in the new issue of PEOPLE.

“I’ve always said, [I’m] very lucky to have started working with Marty in my late 20s and done all these projects together,” says De Niro, who has made 10 feature-length films with Scorsese starting with 1973’s Mean Streets.

Their latest collaboration, Killers of the Flower Moon, is nominated for 10 Oscars, including individual nods for both of them (Best Supporting Actor for De Niro and Best Director for Scorsese)

The two men both grew up in New York City. “We knew each other when we were teenagers,” says De Niro. But they didn’t truly connect at the time.

“We finally met at Christmas dinner years later and I saw Who’s That Knocking [at My Door], and I said, ‘That was a really terrific movie,’ ” recalls De Niro, referring to Scorsese’s 1965 film. “He said, ‘I have the script.’ And Mean Streets was at that time called Season of the Witch, and so that’s how it started.”

The pair went on to make Taxi Driver, New York, New York, Raging Bull, The King of Comedy, Goodfellas, Cape Fear, Casino, The Irishman and Killers of the Flower Moon. They also made a comedic short film called The Audition.

After working together for so many years, the two have a shorthand “in some ways,” says De Niro. “I always say this, he’s good with everyone. He allows people to do what they can do best and then he’ll direct from there.”

“He has very clear ideas but knows not to impose anything and let the people just feel free enough to be expressed as much as they can through whatever they’re doing,” he continues.

For his part, Scorsese is impressed by De Niro’s dedication to taking on whatever role he’s playing, whether it’s gaining 60 lbs. to play boxer Jake LaMotta in Raging Bull, or learning to speak the Osage language in Killers of the Flower Moon, the true story of Indigenous people in 1920s Oklahoma who were murdered by White people for their oil-rich land.

“When Bob commits to a role, he starts digging in with research, questions about absolutely everything, from what the character wears to what he eats for breakfast,” says Scorsese.

“The search and the discoveries never stop. He really did fall in love with the language as he went along — at one point, he said that he wanted to do most of his lines in Osage!” he continues.

Asked what he treasures most about his friendship with De Niro, Scorsese points to its enduring nature.

“At this point, I treasure the sheer longevity, the shared experience and knowledge,” he says. “The trust. The love. And also, the desire to explore together, to go further.”