Years after beginning work on the epic historical drama “Chief of War,” Luciane Buchanan still can’t quite believe it exists—and that she’s a part of it.

Following her breakout role as tech entrepreneur Rose Larkin on Netflix’s “The Night Agent,” the New Zealand native returned home to film “Chief of War,” the Apple TV+ limited series created by Jason Momoa and Thomas Paʻa Sibbett. The show, which premieres Aug. 1, chronicles the 18th century war among the four kingdoms of the Hawaiian islands that led to their unionization and colonization.

Momoa leads the cast as the real-life ferocious warrior Kaʻiana; but Buchanan brings the soul as the powerful and savvy queen, Kaʻahumanu. “[On] my first day, Jason snuck me into the production office. They had all the cast pictures on the wall. There was a picture of Jason, and then there was a picture of me; and then next to me was Temuera Morrison, who’s a [New Zealand] national treasure, and then another national treasure, Cliff Curtis,” she recalls. “And I thought, This is insane—I think I need to go home and just process everything. Because it was a lot to take in, but in the best way.”

Here, Buchanan discusses diving into this true story and finding her strength in the process.

What initially grabbed you about “Chief of War”?

The fact that Apple TV+ was wanting to make a Polynesian historical drama. I had to read the email a couple of times to be like, Oh, they’re really doing this. I never thought in my lifetime that there would be something like this, and so I wanted to be a part of it in whatever capacity.

Then, when I was auditioning, I started to look into Kaʻahumanu. I thought, Who is this person, and why didn’t I know about her? There are so many ways to play her, and that’s so exciting for an actor. Some really look up to her as a historical figure, and others have their own opinions about her and how she changed the trajectory of Hawaiian history. It’s not my place to judge. [For me,] it was just: What do I think she was thinking at this moment in time? I feel lucky that I got an experience like this so early on in my career.

You broke through with American audiences in the present-day setting of “The Night Agent.” What was it like stepping into a period piece, and this very different world and character?

Growing up, I didn’t think I’d ever be part of a period piece. Now we have [projects] like “Bridgerton,” which I know is fictional, but I was like, I’ll never be in the Elizabethan era—I don’t physically look like that. So this was refreshing and a lovely surprise.

I kind of did “Chief of War” and “Night Agent” in tandem. It was just, get the American accent out and get the Hawaiian language back in. So it wasn’t hard to turn Rose off; it was just, “Let’s park you over there for now.”

What did you find to be the most challenging aspect of the project or performance?

Initially, learning the Hawaiian language petrified me. I called my friend who was learning it, and I said, “Girl, I can’t do this.” And she was like, “Just lean into the fear. You are going to get it wrong, and you’re going to get it wrong until you get it right. So give yourself some grace.”

I had an amazing coach who took me under her wing. I’m actually quite annoying to work with, because I’m like, “Every Sunday, [I need] three hours of practice.” And they’re like, “I think you’re OK, but we can do this.” And I’m a very visual person, so I made a family tree of everyone in our story because I was getting confused. Everyone’s name starts with a K; everyone’s kind of cousins, and they’re marrying each other and named after each other. I was thinking, Hold on, I need to break this down.

Another challenge was holding a musket. I am 5’2″; the musket is the same size as me. I remember Jason looking at me [and saying], “This is meant to be a really badass moment and your arms are shaking.” [Laughs] But the armorer found me a slightly smaller one.

What’s your wildest audition story?

For an upcoming film, [Sébastien Vanicek’s] “Evil Dead Burn,” I was in Mexico City; it was midnight, and everyone was Zooming from Paris, New Zealand, and Australia. My character smokes in the scene, so I went down to the shop to buy a cigarette, because I didn’t want to mime it. I accidentally lit the cigarette in this Airbnb, and I was trying to put it out because I definitely couldn’t smoke in there. The walls were very thin, so I was mindful of people sleeping next door, and I felt a bit funny. I was like, Maybe I’m a little bit nervous.

Turns out I had food poisoning, and I spent the entire night over the toilet bowl. I woke up in the afternoon and had a message that I got the part. So I don’t know what happened there. I wouldn’t say it was my best work, but it might have been right for the role. It was a scene where I had to be a little crazy!

Is there a project or role that has had the biggest impact on you so far in your career?

I really believe it was [“Chief of War”]. I think the character was inspiring me as an actor at the same time I was playing her. I really found my voice as an artist and was able to fight for things that I felt were necessary for this character. I found my power in that, and I truly felt empowered to help the other cast members and be like, “You’ve got that idea—say it.” And they were like, “I can’t! I’m number whatever on the call sheet.” And I’d say, “Moses [Goods] has an idea!”

Whereas in the past, it was just, do as you’re told; you’re so lucky to be here. I was so focused on pleasing the director: “Was that good? Was that how you saw the character?” But now I’m at a stage where I need to get something back, too. It’s a collaboration, and I want to have a say in so many aspects of the story. But that took me a really long time to understand. Kaʻahumanu’s strength taught me that, because she was such a leader in her own right.

After stepping off this job, I’m no longer afraid to say the things that I think need to be said. And that sounds kind of confrontational, but it’s actually the best way to make the project the best.