Warner Bros is reportedly developing a new film set in the universe of “Game of Thrones”, focusing on the legendary conquest of Westeros by Aegon I Targaryen.

According to reports, the studio has enlisted writer Beau Willimon — known for his work on “Andor” and “House of Cards” — to develop the screenplay. The project is being planned as a large-scale feature film and would mark the first big-screen adaptation of “A Song of Ice and Fire”, the literary saga by George R. R. Martin that inspired the hit HBO franchise.

The story will reportedly centre on Aegon I Targaryen’s campaign to unite the fractured kingdoms of Westeros. In the lore of the series, Aegon and his sister-wives used three dragons to conquer rival rulers, fundamentally altering the balance of power across the continent.

The origins and history of the Targaryen dynasty are chronicled in Martin’s book “Fire and Blood”. Portions of that work previously served as the basis for the HBO series House of the Dragon, which depicts the Targaryen civil war known as the “Dance of the Dragons”.

The proposed film would take place roughly 300 years before the events of “Game of Thrones” and about 120 years before “House of the Dragon”. Details regarding casting, production timeline and release date have not yet been announced.

The concept of a “Game of Thrones” movie has circulated before. In 2013, original showrunners David Benioff and Dan Weiss had proposed concluding the series with a trilogy of films, though HBO ultimately chose to finish the story on television.

The franchise continues to expand on screen. “House of the Dragon” is expected to return for a third season this summer, while another spinoff, “A Knight of the Seven Kingdoms”, is also moving forward with further seasons. Reports have also suggested the development of an animated project centred on the character known as the Sea Snake.