“The Witcher” writer Declan De Barra is teaming up with new outfit Sleeper Films for television drama “Corballymore House.”

Inspired by De Barra’s own family history, the series is set in a remote Manor House before the First World War. De Barra will act as showrunner on the series, which is being.co-produced by Ben Grass of Pure Grass Films while Diane Ademu-John (“The Haunting of Bly Manor”) boards as creative consultant and exec producer. It will soon be pitched to select buyers.

Sleeper Films, which has offices in London and Dublin, is the new company from Lee Magiday (“The Favourite”), Rory Gilmartin (“Herself”) and Wilf Varvill. It is backed by MediaNet Partners and Sampsonic Media.

BAFTA Award-winner Magiday, who previously worked at Focus Features and Universal Pictures International, and former Element Pictures in-house producer Gilmartin, each bring with them decades of experience in the audio-visual industry. Varvill previously worked in acquisitions at Focus Features and Universal Pictures International and has a wealth of experience as a film and TV completion guarantor.

The company has already put in place an advanced development slate including “In the Shadows” with Film4 and “The Ruín,” an adaptation of Dervla McTiernan’s novel. They are also producing a project with Colin Farrell.

“We’re delighted to be partnering with MediaNet and Sampsonic Media as we move forward into this exciting new period of growth for Sleeper. Our new partners share our passion for compelling story-telling from distinctive talent – stories that have something unique to say about the human condition; stories that can push boundaries and genres,” said Lee Magiday, Rory Gilmartin and Wilf Varvill in a statement.