For 75 years, the story of World War II has largely been written by men, for men. In 2015, Sarah Rose decided she would change that. Rose, who has female friends in the military, was lounging in a hot tub in Hawaii when she wondered, ‘Who was the first woman in war?’ A few Google searches later, she found her answer.

“I came across this corps of 39 women that nobody knew about, in America anyway, who were considered the first women in combat,” says Rose. “They had been in combat 75 years before America lifted the combat exclusion rule so that immediately got me interested.”

That search inspired Rose to pen her second book, “D-Day Girls: The Spies Who Armed the Resistance, Sabotaged the Nazis and Helped Win World War II,” out April 23. “D-Day Girls” details the stories of female members of Britain’s highly secretive Special Operations Executive, a group of spies that ultimately made it possible for the Allies to defeat the Nazis in WWII.

Rose has long been fascinated by the idea of women in the military — partially because she knows women who serve, and partially because they defy patriarchal notions of what it means to be female. “We have such a G.I. Joe, masculine vision of what the military is,” says Rose. “And all of these women are hardcore and tough as nails, but they’re feminine, they’re flirty, and they’re super-accomplished and confident.”