The white horse Rachel Weisz rides in the film had been trained for the TV series Game of Thrones (2011) and was taught to 'play dead' when its rider tugged hard on the left rein. Being unaware of this, at one point Rachel got partially trapped under the horse's left flank for a brief period after it rolled over onto its left side.
For this role, Rachel Weisz had to learn to ride a horse side-saddle, a feat made more challenging by her costume.
Rachel Weisz was costumed by Dinah Collin, who aimed for a fashion foreign to Cornwall, and consulted portraits to create an authentic upper-class appearance.
The country estate house used for filming was inherited by Bamber Gascoigne following the death of his aunt, Mary Innes-Ker, Duchess of Roxburghe, on July 2nd, 2014.
The crew decided on only two main dresses for the Rachel character, since she was not at home in Cornwall.
In the DVD commentary director Roger Michell states that they filmed on location in Devon near the Cornwall border, but avoided filming in Cornwall or setting the film there, because the county features largely in the popular period TV drama Poldark (2015) and he wanted to avoid another period drama set in the same location and too close comparison between the two productions.
Sam Claflin and Holliday Grainger have previously appeared together in The Riot Club (2014) and the TV mini-series Any Human Heart (2010).
Sam Claflin said that beside Rachel Weisz he grew up as an actor on the big screen.