Suranne Jones and Sophie Rundle will play lovers in a new period drama.
The 'Doctor Foster' actress has long been attached to Sally Wainwright's eight-episode series 'Gentleman Jack', which is a true story set in the North of England in the early 1800s.
Suranne will portray Anne Lister, who was born into a military family and inherited a vast estate just outside Halifax from her uncle, while 'Peaky Blinders' star Sophie portrays the wealthy Ann Walker.
The two women swore their love for one another on the Bible and a priest later blessed their relationship in church.
Though their romance was public - and caused Anne to clash with many businessmen - Suranne's character kept intimate details about their relationship concealed in diaries written in a special code which used combinations of Greek letters and numbers.
But director Sally and her research team were able to find the key to unravel the code and will be using the information for the screenplay.
Also starring in the BBC1 show - which is being made in partnership with HBO - are Timothy West, Joe Armstrong, and Vincent Franklin, who, like Sophie, have all worked with Sally in the past.
Additionally, 'Game of Thrones' star Gemma Wheelan will play Marian, Anne's sister, and Gemma Jones will portray their aunt. Stephanie Cole has been cast as Ann's aunt, with Peter Davison as her cousin and Amelia Bullmore as his wife.
'Downton Abbey' actor Thomas Howes, Jodhi May, Rosie Cavaliero, Jessica Baglow and newcomer Albane Courtois have also bagged roles on the show.
Sally said: "I'm delighted that the story of Anne Lister has attracted such a talented, standout cast.
"We also have a wonderful crew on board and I can't wait to start filming."
Filming will take place in and around Halifax, as well as overseas in Copenhagen and 'Gentleman Jack' is expected to air in late 2019.
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