A United Kingdom is a 2016 British biographical romantic drama film directed by Amma Asante and written by Guy Hibbert, based on the true-life romance between Sir Seretse Khama and his wife Ruth Williams Khama.[ David Oyelowo and Rosamund Pike portray Seretse and Ruth, respectively.
The film is based on the true story of the heir to the throne of Bechuanaland, Seretse Khama of the Bamangwato tribe, who studies law in London immediately after World War II. There he meets a White woman (Ruth Williams) whom he eventually marries, despite the protests of their families, and opposition from the British government, which is concerned about relations with South Africa and the stability of the entire region of Southern Africa.
Seretse discovers that the British have allowed a US mining corporation to prospect for precious stones, and is eager to make sure that, if anything is found, the exploitation of the country’s resources should solely be done by the people of Bechuanaland.
Seretse wants his people to support him as king and manages to win their backing, while the British government decides to exile him from his own country. Meanwhile, Ruth has their baby in Bechuanaland and becomes accepted by the local people by “walking the road with them”. When the British want to proclaim an administrator to the Bechuana people instead of their king, the tribe refuses to convene a meeting to so do. During this time, diamonds are found and Seretse makes sure that the British government publicly declares that the Bechuana people have the sole right to exploit these resources.