The series is based on Mary S. Lovell's biography 'The Mitford Girls', which was published under the title 'The Sisters' in the USA, and was adapted for television by writer Sarah Williams.

Executive producer Matthew Mosley is the great-grandson of Oswald Mosley through his first wife Cynthia, and the character of Oswald Mosley is played by Joshua Sasse in the series.

Matthew Mosley described seeing actor Joshua Sasse in character as his own great-grandfather Oswald Mosley on set for the first time as 'quite surreal.'

Filming took place in June 2024 across the UK, including at St Mary the Virgin's Church in Aylesbury, Buckinghamshire, and Tring Park Mansion in Hertfordshire.

First look images from the filming were released in August 2024, ahead of the series' premiere.

On Rotten Tomatoes, the series holds an 88% approval rating based on 25 critic reviews, with the consensus praising its 'slick presentation and superb acting' in depicting the lure of fascism.

Metacritic gave the series a weighted average score of 74 out of 100 based on 7 critics, indicating 'generally favorable' reviews.

The series premiered on 19 June 2025 on BritBox in the United States and on U&Drama in the United Kingdom, later airing on BBC One and BBC iPlayer on 14 June 2026.