Rosamund Pike (Gone Girl) and David Oyelowo (Interstellar) are both negotiating for roles in the big screen drama A United Kingdom from Belle director Amma Asante.

The film tells the true story of a member of the royal family of the African nation of Bechuanaland, the former English colony that eventually became Botswana. Khama was the country’s first president. His marriage to a white woman, Ruth Williams, in 1948 gave rise to international outrage. Considered scandalous around the world, the union met with a sharp backlash in South Africa, where interracial marriage was illegal, and led Great Britain to ban Khama from his homeland in 1951.

The screenplay was written by British TV writer Guy Hibbert (Prime Suspect).

Oyelowo, who is also one of the movie’s producers, expressed enthusiasm over the prospect of teaming up with Pike and Asante, calling them, “two of the most exciting talents working in film today.” He continued, “I’ve worked with both of them before and so my excitement about them joining A United Kingdom stems from a knowledge of just how inspiring they are to work with and how much daring and beauty they will bring to this epic love story.”

Members of the Khama family, who have been cooperating with the filmmakers and are involved with the development of the project, are pleased with the idea of Oyelowo portraying Seretse.

Oyelowo memorably played Martin Luther King Jr. in the 2014 film Selma. He is currently starring in the HBO drama Nightingale.

A United Kingdom is expected to begin filming in October.