Davis said this is a film where she pushed herself in a way she's never done in her own storied career.
PHILADELPHIA (WPVI) -- It's being called more of a movement than a movie.
Oscar-winning actress Viola Davis said her new film, "The Woman King," is her magnum opus, one of the most important works of her career.
Based on a true story, a real tribe of female warriors in West Africa, Davis brings a star-studded, powerhouse cast of dark-skinned Black actors to the forefront.
It's a film where she also pushed herself in a way she's never done in her own storied career.
"Sometimes your work can heal you," Davis said. "It really can."
It's hard to believe that this is Davis' first action film.
"Brutal," she said. "It was brutal. It was painful. It was maddening. It was joyful. It was cathartic."
Davis plays Nanisca, the leader of the Agojie, an all-women warrior army in the African kingdom of Dahomey.
"For me to see the possibilities within myself," Davis asked, "Are you kidding me? As a woman over 50, my whole acting training has been defined by everything I could not do. Everyone would say, 'You can't do this. You can't do that. There's no rules for this. There's no rules for that.' That's the generation I came from."
She said the training was beyond intense.
"The fact that I'm still alive, and I didn't have a heart attack when I was sprinting on the treadmill," she laughed.
This is South African actress Thuso Mbedu's big screen debut. She works alongside Davis, calling it a bucket list moment that she feels she manifested.
"It really is unlike anything I could have ever imagined," Mbedu said. "I'm grateful for it and stronger for it."
Add to the cast, Lashana Lynch, fresh from the Marvel Universe and a newly named 007.
"I've made two strong choices," Lynch said. "But this is different. This is for us. And I can really say that this is solely for us, by us, with us, around us. This is our energy. Everything about this movie is a proud moment."
The Woman King opens in theaters on September 16.