Idris Elba's New Project Has Emotional Connection to the Grandfather He Never Knew (Exclusive)

Idris Elba says his latest project resulted in some self-reflection on his family and their role in one of the most important conflicts in modern history.

Elba tells PEOPLE that his role as narrator and executive producer of Erased: WW2's Heroes of Color, a new National Geographic docuseries highlighting the often-forgotten stories of soldiers of color, made him think about his own grandfather, who served during World War II, but whom the star knows very little about.

"Every time there [were] real restored pictures of the soldiers of the time, of any footage, it really did strike a heartstring for me because my mom doesn't have a single picture of her dad, whether in uniform or not," the actor explains. "I have never seen an actual image of my granddad and I just imagined him being one of these guys."

The Knuckles star continues by noting that emotions ran particularly high for him, "especially during the voiceover moments."

"I just would suppress them because this is not about me, but man, I was like, I dunno, that could be my granddad in the back there, you know?" he adds. "I dunno. It was like he was six foot seven, so I was scanning for the tall guys."

For his mom, who was 10 when her father died, her memories are "filled with melancholy."

"There's so much history about my grandfather that she doesn't know because she only knew him for a short time," he says.

Due to his own personal connection, Elba said that the opportunity to work on the project and "reframe what people know about the history" and "presence of Black and brown soldiers" in WWII "really did resonate with me in a different way."

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And in "watching these stories being told," Elba concedes that the struggles soldiers went through at the time "really hit home" for the first time.

"It wasn't until I really heard these accounts of how that must have felt, that it really hit home how significant these stories are. How traumatic it must have been for these young people," he shares. "When you listen to that and you hear it firsthand, you really put stuff into perspective."

Each episode of Erased: WW2's Heroes of Color highlights at least three different historical accounts of soldiers of color who laid their lives down to defend their countries.

"I feel like it is really important for history to be accurate," the star notes. "We don't get growth from inaccurate history. We get growth from knowing what was there before and that's really important."

Erased: WW2's Heroes of Color premieres on June 3 on National Geographic and will stream on Disney+ and Hulu starting June 4.