Epix has boarded Downton Abbey creator Julian Fellowes’ forthcoming period drama Belgravia – the ITV series first revealed by Deadline last month.

The U.S. cable network is co-producing the Carnival Films drama with the British commercial broadcaster and will air it day-and-date with the UK debut. The series will begin production later this spring. Casting is currently underway.

It is a boon for the MGM-owned network; Fellowes’ previous hit Downton Abbey aired on PBS Masterpiece in the U.S.

The six-part series is based on Fellowes’ novel Belgravia, a tale of secrets and scandals set in 1840s London. The drama is set in the 19th Century, around seventy years before Downton, when the upper echelons of society began to rub shoulders the emerging industrial nouveau riche. But the story begins on the eve of the Battle of Waterloo in 1815, when the Duchess of Richmond throws a party in Brussels for the Duke of Wellington. Among the guests are James and Anne Trenchard, who are living on the profits of newfound trading success. Their young daughter Sophia has caught the eye of Edmund Bellasis, the son and heir of one of the richest and most prominent families in England. Twenty-five years later, when the two families are settled into the newly developed area of Belgravia, the events of the ball, and the secrets, still resonate.

The book, which was published in 2016, was originally published online in a serial format, similar to that of Charles Dickens’ novels, albeit originally via an app that also included an audiobook narration by Truly, Madly, Deeply star Juliet Stevenson.

Fellowes is adapting his own novel and the drama is being directed by John Alexander, who has directed series such as BBC thriller Trust Me and Sky’s Jamestown. It is exec produced by Carnival Films Executive Chairman Gareth Neame, Nigel Marchant and Liz Trubridge and produced by Killing Eve producer Colin Wratten.

Neame said, “It’s fantastic to be working once again with Julian, a master storyteller. In Belgravia he has painted a wonderful backdrop of 19th century society against which intrigue and dynastic power struggles will play out. We are delighted to be partnering with ITV once again and look forward to working with Epix to introduce U.S. audiences to this fantastic event series.”

“Belgravia is everything we could ask for – great storytelling, incredible production value and top-notch auspices,” said Epix President Michael Wright. “It absolutely defines the kind of programming we’re looking for at Epix, and we can’t wait to dive in with our partners at Carnival Films and ITV – along with this terrific creative team – to bring Belgravia to life.”

Polly Hill, Head of Drama, ITV added, “We’re delighted to be reuniting with Julian Fellowes, Gareth Neame and Carnival Films to produce Belgravia for ITV. It’s a tale of scandal and intrigue set in 1840s London with some wonderful characters spanning two generations at its heart.”

NBCUniversal International Distribution holds global rights.