The historical epic inspired by the true story of an all-female African army struggled for survival, 

"When you get a film and the players are players that have never been seen before and in a genre like this it's a fight" to get made, says Davis

speaking by video from the Toronto Film Festival, where the movie directed by Gina Prince-Bythewood made its debut.

 "A day-to-day fight. Literally, I was Nanisca." says Davis

But let's back up. "The Woman King" (in theaters Friday), set in the Dahomey kingdom of western Africa in 1823, 

tells the story of the Agojie, a military regiment of women soldiers protecting its people from threats of invasion.

At the heart of the epic is Nanisca (Viola Davis), the skilled warrior general with the ear of King Ghezo (John Boyega),

with her right-hand soldiers Amenza (Sheila Atim) and Izogie (Lashana Lynch) – and young recruit Nawi– next to her in battle.

The women of "The Woman King" underwent months of physical and mental preparation to get into fighting shape. 

Davis, 57, bulked up to play the hardened leader; Mbedu, 31, needed to look the part of a fresh-faced rookie climbing the ranks.