The late monarch died on Sept. 8.
Oprah Winfrey is mourning Queen Elizabeth II's death. ET's Rachel Smith spoke with the 68-year-old TV personality at the premiere of Sidney during the 2022 Toronto International Film Festival, and Winfrey shared where she was at the time that the U.K.'s longest-serving monarch died.
"I was hiking in Maui when I heard that she passed," Winfrey said. "I think losing her is losing one of the great women of service in the world. Nobody's done it better."
Earlier in the day, ET spoke with Winfrey and Reginald Hudlin, who, respectively, produced and directed Sidney, the upcoming documentary on Sidney Poitier's life and work. The famed actor, who was knighted by Queen Elizabeth in 1974, died in January.
The film includes footage of Poitier himself, which came from a two day-long interview Winfrey did with him in 2012.
"That interview ended up going for two days because he started telling stories and then I'd say, 'Remember the story about? Remember the time that? Remember the time that?'" Winfrey recalled. "... All that footage had never been seen until this. I realized it was such a special moment, as this [is], because he said, 'That's all my family has is my story.'"
According to Hudlin, that footage "became the spine of the film," and was one of the many reasons he was happy to have Winfrey onboard with the project.
"No one has a more encyclopedic knowledge of Sidney Poitier, has the intimate relationships with him and his family than her," he told ET. "When we came together we were like, 'OK, let's rock.' We just got to work. It was a wonderful process, because we were both motivated by the same thing."
That motivation, Winfrey said, was "to guard and protect the story, and to honor the story in a way that he honored his own life."
"That's what you see when you're looking at this film," she said. "You're looking at somebody who lived their life in a state of choosing excellence every single day, somebody who, no matter who he met -- whether it was somebody working in the kitchen or somebody taking his car for valet -- he was as curious about their life as he is anybody else in the world."
"I think his single most important act was remaining fully, wholly himself at all times," Winfrey added. "Through being himself, what we're looking at with his art... it's just an expression of the true man... There is no more extraordinary human being that I've known than Sidney Poitier."
Sidney premieres Sept 23 on AppleTV+.