Annette Bening on finding out Robert De Niro went to class with the actress she portrays in her latest movie

"It was hard to find out a lot about Gloria."

— -- To prepare for her latest role, Annette Bening did some intense research.

Bening stars as the Academy Award-winning actress Gloria Grahame in the new movie “Film Stars Don’t Die in Liverpool.”

“I wanted to find out everything about Gloria,” Bening, 59, said in an interview for ABC News’ “Popcorn With Peter Travers.”

The film tells the real-life story of Grahame’s life and late career while she lived in the U.K. and battled breast cancer toward the end of her life.

Grahame won an Oscar for best supporting actress in 1953, for her role in the film “The Bad and the Beautiful.”

Bening said in her preparation for the film, she spoke to actress Terry Moore, a friend of Grahame’s who was also nominated for a best supporting actress in 1953.

“She was kind enough to talk to me. She said she was a friend of Gloria’s, and Terry said she was awesome. She was super fun, a loyal friend and also incredibly private, which was reassuring for me to hear because it was hard to find out a lot about Gloria,” Bening said.

Bening said she also learned that her friend, actor Robert De Niro, had taken acting classes with Grahame. De Niro had studied with the legendary acting teacher Stella Adler.

“Someone said to him, ‘You know who that is over there? That’s Gloria Grahame.’ And Bob said -- well, he didn’t know who she was even. He certainly didn’t recognize her even when someone said that was her, because a lot of people just didn’t,” Bening said. “He said she would not get up and do scenes, but she would just sit and listen to the lectures. And I thought, ‘OK, that’s kind of impressive.’ She’s already had this big career. She won an Academy Award. And there she is in acting class in New York.”

Bening said she knows it’s ironic that she struggled to find information about the private Grahame, considering she herself doesn’t like to share much about her own life.

“I’m a pretty private person. I’m trying to be more open in my work, but in my -- yeah, I’m really relatively private, which is doable,” said Bening.

Since making the movie, Bening said she’s learned more about Grahame through the stories of people who knew her.

“I’d got to a screening and an actor will come up and say, 'Oh my god, I made a movie with Gloria in the '70s,' you know, and then they’ll tell me a story about Gloria and how they’d go to lunch and have a good time,” Bening said. “I love that about her. I respect that. I really respect that.”

Watch the full interview with the "Film Stars Don't Die in Liverpool" star Annette Bening in the video above.

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