Following the ambitious adventure saga “The Three Musketeers,” Pathé and Chapter 2 are back at work on another epic franchise, this time in English with a plot shedding light on the origins of the Grimaldi dynasty and their conquest of Monaco in the late 13th century. While they’re lesser known than the U.K.’s Windsors, the Grimaldi family has ruled Monaco for eight centuries and as such remains Europe’s longest-ruling royal family.

Martha Hillier (“The Last Kingdom,” “Versailles”) is attached to write the first installment of “Monaco,” which is titled “Part I — The Rock.” Astrea Films is producing the film with Chapter 2, a Mediawan Company, and Pathé. Astrea is headed by Andrea, Pierre and Beatrice Casiraghi, who have ties to the Grimaldi family, while Dimitri Rassam is also part of the Monegasque princely family through his marriage with Charlotte Casiraghi. Morgan O’Sullivan (“The Last Duel,” “Vikings”) and OSP’s Liz Gill (“Dangerous Liaisons,” “Vikings”) are attached to executive produce.

Beyond this first film, the producers are looking to expand the franchise into several movies and TV series that will chart the adventures of the family throughout the centuries.

“I thought I knew this story but it turns out I had only scratched the surface. Simply said it is epic in every way: Family, adventure, intrigue,” said Rassam. “The true story of the foundation of the Grimaldis of Monaco some seven centuries ago is one of the most captivating stories I have had the chance of discovering thanks to the initiative of Beatrice, Andrea and Pierre,” added the producer.

Astrea, meanwhile, said the project was initiated by Andrea Casiraghi when he “started exploring the archives of the palace in search of the most compelling untold stories.”

“We were overwhelmed by the amount of untold, intriguing and epic tales that were hidden in ancient documents and private correspondence throughout the centuries. Ultimately we decided to start at the beginning. Martha Hillier brought her passion and talent into telling the Grimaldi’s origin story by carving from those archives the most layered, witty and authentic characters,” Astrea said in a statement.

Pathé’s CEO Ardavan Safaee pointed out that after the success of “The Three Musketeers,” he and Rassam were looking for English-language projects to team up on “to propose to the international market.”

“The incredible story of the Grimaldis throughout the ages allow for stories to be told over generations, in the vein of what was brilliantly achieved with ‘Yellowstone,'” said Safaee, adding that Pathé “feels there is an almost unlimited potential with this IP whether for the movie theaters or in the series format.”

The producers, who are currently at the Cannes Film Festival, are eyeing a start of production mid-2024 and are currently engaging in conversations to attach talent.