The latest project from Shondaland, and the first one to come from the deal with Netflix that Shonda Rhimes inked, is the Regency romance Bridgerton. Arriving on December 25, the saucy and scandalous - yet prim and proper - series revolves around an arrangement between the innocent Daphne Bridgerton (Phoebe Dynevor) and the playboy Duke Simon Basset (Regé-Jean Page) which soon blossoms into something more.

Although, of course, there is much more to the series than one couple's journey. After all, two families lie at the center of the story: the Bridgertons and the Featheringtons. To add onto their shenanigans, there is Queen Charlotte moving her subjects around like chess pieces, friends and neighbors like Simon's guardian Lady Danbury, and the mysterious Gossip Girl of the ton, Lady Whistledown herself.

Related: Netflix’s Bridgerton Show First Look Images Confirm Christmas Release Date

With all those plates spinning in the air at once, showrunner Chris Van Dusen has his work cut out for him. The writer and executive producer spoke to Screen Rant about the attraction of the source material (the eponymous novel series by Julia Quinn), the inspirations behind certain show-only additions, and the importance of getting the casting just right.

Phoebe Dynevor as Daphne and Rege-John Page as Simon in Bridgerton

You have been with Shondaland for years now, but Bridgerton seems like it's really your baby. What led to you adapting it? 

Chris Van Dusen: I was a writer and producer on Scandal, and as that show was coming to an end, I was talking to Shonda about what I wanted to do next. I really wanted to do something different than modern-day political intrigue on Capitol Hill, so Shonda is the one that first told me about the books. I went home, and I read the first book that night. And then I read the second book the second night, and the third, fourth, and so on and so on.

I was immediately hooked, and I just devoured them. I feel like they had every element that I'm always drawn to; they were emotional, and they were funny, and they were sexy and steamy. Then there was this delightful family at the center of everything, so I was just really drawn into their world. The larger thing that struck me was that this was a chance to make a show that married history and fantasy in a really exciting way.

Speaking of history, aside from the source material itself, what research did you do to explore the wide array of social classes you included in the series?

Chris Van Dusen: We worked with a number of historians. When I was developing and writing the show, we had a number of consultants. And when we were shooting the show, we worked with a wonderful historian named Dr. Hannah Greig, who was on set every day.

There are so many rules of this world. A young lady has to know how to curtsy to the queen, for example; she has to know how to enter a room. A young gentleman also needs to know about the behaviors that are acceptable as well. Even when having dinners together, how one sits at the table, and how you hold your silverware - just the layout and the rules. Hannah and our other historians really were essential for understanding the schedule of things.

But the show is really for a modern audience, so there's a modernity to the themes and characters, and the stories we tell. Everything's told through our own contemporary lens, so it wasn't such a stretch to take certain creative liberties. It's a reimagined world.

And in that reimagined world, the diversity was very refreshing. It's something I would expect from Shondaland, but I found it super interesting that there was an in-universe explanation for it. How did decide to incorporate the diversity into the story instead of just letting it exist without comment?

Chris Van Dusen: We knew from the beginning that we wanted to make the show reflect the world that we live in today. Even though it's set in the 19th century, we wanted modern audiences to relate to it - and that's something Shondaland does, ever since Grey's Anatomy. I worked on Grey's Anatomy, and we always be cast the best actors for the roles in ways that represent the world today.

We had a really interesting opportunity to do that with Bridgerton, that's set in the 19th century. Early on in the research, there was this fascinating fact about Queen Charlotte: the idea that she was really England's first Queen of mixed race, and that she had African ancestry. A lot of historians believe there's evidence for that, and that idea was just so fascinating to me. Because it just made me wonder, what would that really look like? What could that look like, and what could she have done?

Talking about that whole thing of marrying history and fantasy, this was rooted in history but it's such a fantastical jumping off point. Perhaps Queen Charlotte could have elevated other people of color in society; she could have given them titles and lands and dukedoms. That's really the idea that the Simon of the series was born out of, and I think we get to explore it in a really fascinating way.

I loved Simon and Daphne's story in season one, but the series has a large ensemble cast, and every book has stories for different members of the family. How do you cast with the long term stories in mind, and what qualities stood out most when auditioning actors?

Chris Van Dusen: You know, it's true. We have an amazing, sprawling cast and a diverse one, not just in terms of terms of ethnicities, but also ages and experiences. The world of Bridgerton is massive; we have the Bridgerton family and we have the Featherington family, and then we have people like Lady Danbury and other characters like that. And as you said, there's new characters for the series, like Queen Charlotte. She's someone I wanted to add just to fill out the world.

We expand on the books a lot in the show; it isn't just about the Bridgertons, it's about a world and a society. We worked with a great casting director in the UK,  Kelly Valentine Hendry, and we really scoured the film and television and theater scene there. And we found some amazing actors that just elevated the material and brought the characters to life in such amazing ways.

I was particularly intrigued by Eloise and Penelope , who feel like the most like modern characters. What was it like casting them specifically, because their friendship and chemistry is as important as their self-imposed status of being outsiders?

Chris Van Dusen: They are friends in real life, and I think that friendship really translates to the screen. In the writers' room, we refer to them as PenEloise. That's slowly becoming a thing, as the fans of the books tweet and are on Instagram. I think they're using that hashtag a lot.

They are so funny together, on screen and off. I feel like they're fan favorites, for a lot of reasons. Eloise, especially, is rebellious; she's very vocal, and she questions things. Penelope is the same way, and they kind of are a perfect friendship. Penelope is a little bit of a wallflower, so we think that she fades into the background. But when she's with Eloise, you see a totally different side of her - she's this super smart, super opinionated and vocal character. I think that it's just so fun to watch the both of them.

They both read for the part during the casting process, and when we saw them, we immediately knew that was Penelope and that was Eloise Bridgerton. I think we have something special with them.

bridgerton - eloise and penelope

I absolutely love how Lady Whistledown feels like a Regency Era Gossip Girl. What inspired you to depict her like that, and to have Julie Andrews of all people reading her saucy columns?

Chris Van Dusen: Yeah, to have Julie Andrews playing this character is just incredible. I still can't believe it's actually a thing that has happened, and the world's gonna get to see it. With Whistledown, we really explore the power of the written word, and how it affects people and changes the narrative. When you watch the show, you really see how much of an effect she has on the story and on the characters.

Julie Andrews did all of her sessions virtually, but it was so fun to work with her. She's everything you would think Julie Andrews is; she's lovely and charming, and she really relishes in the cheeky things, which I thought was a lot of fun. Writing Whistledown was some of the most fun I had writing the show; writing those lines for Whistledown to say. And Julie Andrews brought so much more to it, because she's taking digs at people but in such a signature, bright Julie Andrews kind of way. It's just so fun.

Lady Danbury was one of the standout characters for me this season, especially the way that she brings out the vulnerable side of Simon early on, and how we really get to learn who he is through her eyes. How would you say those characters influence each other, and what impact has she left on him?

Chris Van Dusen: Adjoa Andoh is just an incredible, amazing actress. Some of my favorite scenes are when Lady Danbury and Simon are on screen together. Simon's not your typical Duke, he obviously he wants no part of the marriage market and no part of being married; wants no part of society, really. And over the course of this series, we learn why that is, and it's a tragic story. But I think it's also one filled with hope.

Lady Danbury, really, I think brings that hopeful side out of him in their scenes together. We have a flashback episode of Simon's backstory, and we get to see how Lady Danbury was really integral in helping Simon turn into the Duke that he has become.

Another mother-son dynamic I found fascinating was Anthony and Violet. It's almost a battle of wills when it comes to who's really running the household. How do you craft that loving yet contentious dynamic?

Chris Van Dusen: It's really interesting, because a lot of the show has to do with  his family, and there's this power struggle between Violet and Anthony that we get to follow through the season. Underneath this beautiful escapist world, we have a really modern commentary on how everything has changed in the last 200 years, but nothing has changed by the end of the day. I think that goes for both women and men.

For Anthony, you really get to see how much he battles his duty to his family with just wanting to have fun and pursuing that pleasure. Violet obviously has something to say about that, but society has really dictated both of their roles and he is the head of the family. But when you watch the show, you're questioning whether that is true and how much Violet pushes back on that in some really fun ways.

With such a large cast, you've obviously got to map out so much in advance. But was there any character that changed the most from conception, either through the casting or the writing?

Chris Van Dusen: That's an interesting question. I always say that if the season had a subtitle, it would be "The Education of Daphne Bridgerton." It's really about her. She starts as this picture perfect innocent debutante, then turns into something else entirely. as she finally figures out who she is and what she's capable of.

I think that Phoebe Dynevor brought such an amazing vulnerability to Daphne. It was a little unexpected, to see how she really lived and brought this character to life in amazing ways. She makes you root for Daphne, and she makes you want Daphne to succeed and to figure out who she is as she becomes the woman that she becomes.

More: Bridgerton Trailer: Gossip Girl Meets Jane Austen In New Shondaland Show

Bridgerton's first season begins streaming December 25 on Netflix.