Magnificent Obsession: Robert De Niro on the Set of Raging Bull

If Robert De Niro never acted in any other movies besides those he’s made with his frequent director and collaborator, Martin Scorsese, he’d still be a film legend. Mean Streets, Taxi Driver, Raging Bull, The King of Comedy, Goodfellas — the list goes on and on. Add to those his performances in movies as diverse as The Deer Hunter, The Godfather: Part II, Midnight Run, Cop Land and Silver Linings Playbook, and the scope of the man’s accomplishments comes into formidable focus.

Here, on the occasion of De Niro’s 70th birthday — he was born Aug. 17, 1943, in New York City — TIME presents a fittingly iconic portfolio of pictures by photographer Brian Hamill, made on the set of Raging Bull in 1979. De Niro’s riveting and at-times harrowing portrayal of world middleweight boxing champ Jake LaMotta won him a Best Actor Oscar, and raised the bar for onscreen Method performances when the actor famously gained 60 pounds to play a bloated LaMotta late in life.

TIME talked to De Niro about his recollections of working on what has, over the years, come to be considered one of the greatest American films ever made.

“I read Jake LaMotta’s memoir, Raging Bull: My Story, when I was working on the film 1900 in Italy,” De Niro says, “and I told Marty [Scorsese] to read it. It had heart. It wasn’t a great book, but there was something about it, a jumping-off point, if you will.”

Wholly committed to bringing the book to the screen, De Niro was instrumental in the movie’s development — although it took some persuasion to get Scorsese on board, and a number of years would pass before the film was made.

“We worked with one writer, Mardik Martin, who had worked on Mean Streets, and Mardik and I did a lot of research together. We visited Jake’s wife Vickie, and would go over things in the script. We needed more structure, and Marty thought Paul Schrader [who wrote Taxi Driver] could help — which he did. Then we polished it up with dialog after we had the order of the scenes and knew what it was going to be.”

Scorsese’s assured and inventive direction and the choice to shoot the film in gritty black and white — with the exception of a single, evocative home-movie scene in color — established the mood for the film. De Niro’s full immersion into the role of LaMotta, meanwhile, is the film’s emotional core: visceral and explosive, his performance is also a beautifully nuanced, detailed portrayal of a complex, conflicted and often brutal man. The conscious choice to cast unknown actors, notably Joe Pesci (who plays LaMotta’s bother, Joey) and a then-untried actress named Cathy Moriarty (who plays LaMotta’s second wife, Vickie) adds to the film’s authenticity.

“I thought it was important that [the characters] were real and believable, and certainly Joe and Cathy had these qualities. There was another actor who was younger than Joe, and had [a lot of what we were looking for], but at the end of the day Joe was so much better for what we wanted. He was great. Joe told us about Cathy, a girl who grew up in the Bronx. We met her and we read with her, and felt she was the most interesting for what we needed.”

The choreographed boxing scenes in the film are cited as some of the best sports scenes in movie history. For his part, De Niro was schooled by LaMotta himself.

“I sparred with people with gear on, but we were careful. We weren’t looking to kill anyone. Then I trained with Jake. He would say, ‘Hit me, don’t worry, don’t worry.’ He was 55, but he was really tough. I didn’t realize until I got to his age that you could still take a punch.”

Photographer Hamill describes the film as a real New York movie, shot on the streets of the city. He says De Niro really lived the part, and captured the essence of LaMotta — his rough charisma.

“I’ve known Brian a long time,” the actor notes. “In fact, it’s been so long, I forget where we first met! We hung out with mutual friends. I still run into him once in a while. The pictures he made on the set of that movie are really very special.”

“It wasn’t a big movie,” De Niro says of Raging Bull. “It wasn’t really a hit. But it was a movie we were proud of. All the movies I’ve done with Marty are different, and they’ve all been wonderful experiences.”

Brian Hamill is a New York-based photographer. He has photographed stills for films including Raging Bull, Annie Hall and Manhattan, as well as portraits of John Lennon, Woody Allen and boxing greats including Muhammad Ali, Sugar Ray Robinson and Sonny Liston.

Phil Bicker is a senior photo editor at TIME.