Nelson Mandela Foundation co-hosts A United Kingdom premiere

You can’t help but be inspired by the dramatic story of the love between Botswana’s first democratically elected president, Sir Seretse Khama, and his English wife, Ruth Williams Khama, says Oscar-winning actress Terry Pheto.

Pheto was speaking at the 23 November South African premiere of A United Kingdom, which tracks the Khamas’ 1948 marriage and its political ramifications. It was opposed by the British government, and both their families. Khama was Bamangwato royalty. The Nelson Mandela Foundation partnered with Anant Singh's Videovision Entertainment to premiere the film in South Africa.

Pheto has been nominated for the British Independent Film Award for Best Supporting Actress for her portrayal as Seretse Khama’s sister, Naledi Khama. “It was such an honour. I was so inspired by the beautiful love story,” she said.

The film, which releases commercially in South Africa on 9 December, stars Nigerian actor David Oleweyo as Seretse Khama and English actress Rosamund Pike as Ruth Williams Khama. Pheto said it was “particularly important to watch now, we all have the ability to choose love as a weapon”.

Nelson Mandela Foundation CE Sello Hatang said the film was a reminder that South Africa, and Africa, had not yet escaped its past. “Our past is still our present. Issues of discrimination have not ended. All of us have a responsibility to eliminate all forms of discrimination.

The British government opposed the Khamas’ marriage, which endured until Seretse Khama’s death in 1980, because apartheid South Africa – appalled at a mixed-race couple ruling a neighbouring country – put pressure on it. Britain, then heavily in debt after the end of World War II, needed South Africa’s cheap gold and uranium.

Khama’s uncle, Tshekedi Khama, raised him after his parents were killed in a car accident. Tshekedi Khama demanded Khama annul his marriage to Ruth Williams, whose parents were also unhappy at the union.

“When I first read [the script] I sobbed my eyes out,” said South African actor Theo Landey, who portrays American journalist Nash in the film. “David [Oleweyo] and I sat on that airfield [an airfield featured in the film] and said, we’re proud of it because it is an African story told through a black guy’s narrative. Also, it’s just a bloody good love story.”

The Khamas’ grandson, Dale Ter Haar, said the story of his grandparents’ love affair was “not something we heard about as we grew up. It was something we read about as adults. That is typical of my grandparents. It was just something that happened and they got on with it.”

Seretse Khama, who was reaffirmed by tribal elders as kgosi in 1949, renounced his claim to the Bamangwato throne in 1956 in order to be allowed to return to Botswana, then a British protectorate called Bechuanaland. He and Ruth WIlliams Khama lived there as private citizens until Khama founded the Bechuanaland Democratic Party in 1961. He was elected head of the government in 1965, and Botswana gained independence in 1966.

“Just like the Mandela story plays an important, but small, part in South African history, likewise, this one tells a small but not insignificant part of our legacy …” said another Khama grandson, Marcus Ter Haar. “Botswana is a really small country in the African context. This film really puts Botswana on the map.”

Oleweyo, who recently portrayed American civil rights activist Martin Luther King Jnr in the biopic Semla, said playing Seretse Khama was “truly one of the greatest honours of my career”. Oleweyo was speaking in a pre-recorded message as he is on stage as Othello in London.“We had the most magnificent time making [A United Kingdom],” he said.

Zambian-born actress Abena Ayivor, who portrayed Tshekedi Khama’s wife Ella Khama, said it was “amazing” to star in a film that celebrated Africa’s enormous landscapes, and to portray a woman known for dignity and strength. “I loved every second of it.”

“My grandmother is an ideal role model for me,” said Tahlia Khama. “She stayed true to her desire for true love and didn’t let anyone get in the way.”