The love that dared to speak its name
There are three cinemas in Botswana, a country of 2.2million people and three million cows. At one of them, in the Riverwalk Mall, in the capital, Gaborone, an auspicious event is taking place: the African premiere of Amma Asante's film A United Kingdom, starring David Oyelowo as Seretse Khama, Botswana's first president, and Rosamund Pike as his white British wife, Ruth.
The event is part of a 50th-anniversary celebration of Botswana's independence. The current president, Ian Khama, the democratically elected son of Seretse, sometimes rides around on his motorbike. His modest lifestyle, compared with that of the leaders of some of Africa's more volatile countries, is significant.
There is a remarkable story behind the film, which is based on Susan Williams's book Colour Bar.
Seretse Khama, born in 1921, was the chief-in-waiting of the Bangwato tribe. His father had died when he was four, and the regent was his uncle, Tshekedi Khama. At the time, Botswana was a British protectorate known as Bechuanaland.
Seretse was educated in South Africa (he met Nelson Mandela while both were studying in Johannesburg), before arriving at Balliol College, Oxford, in 1945, then moving to London to study law. In post-war Britain, only 0.02% of the population was black and prejudice was rife.
At a London Missionary Society dance in 1947, Seretse met Ruth Williams, then a clerk with Lloyd's underwriters, and daughter of a tea salesman. They were initially drawn together by a mutual love of jazz. Not long afterwards, he asked her to marry him, but Tshekedi was firmly against it. He thought that when Seretse returned to Bechuanaland to take up his position as chief of the Bangwato, his people would never accept Ruth as mother of the tribe.
He managed to get the planned church wedding stopped; Ruth was sacked from her job and her father disowned her. Nonetheless, the couple were married in a registry office in London on September 29 1948.
Seretse returned to Bechuanaland shortly after his marriage and attended a series of kgotlasto discuss his future. At the third, in June 1949, at least 9000 men turned up.
Seretse gave a moving speech and asked the Bangwato to accept him as chief with Ruth as his wife. At the end he asked that those in support of him stand, and almost all rose in approbation.
Seretse sent a telegram to Ruth in London ("Have been accepted by tribe"), and in August 1949 she travelled to Serowe, the capital of the Bangwato Reserve, welcomed by a cheering crowd along the way.
But the British would not stand back and allow events to take their course, chiefly because of pressure from South Africa, which was officially establishing apartheid, and which the British depended on for gold.
The couple settled in Serowe but it was initially hard for Ruth, who was rejected by the white colonial community, and at first also struggled to establish herself among the African women. (The population at the time was nearly 300000, only about 2000 of whom were white.) By the following year, though, Ruth, who was pregnant, had become popular with the locals.
Seretse was tricked into returning to the UK and then banished from Bechuanaland for life by the government. The spurious reason given was that Seretse's return to Bechuanaland would endanger peace and good government there.
The Bangwato even sent a telegram to Queen Elizabeth to plead for the return of their chief, and in 1956 Seretse and Ruth, along with their two children, were allowed home. Seretse renounced the chieftainship and founded the Bechuanaland Democratic Party, becoming the founding president of Botswana in 1966, when the country became independent.
Seretse and Ruth had two more children. Seretse died of cancer in 1980, aged only 59, but Ruth remained in Botswana. She lived by herself on a farm, and died in 2002. Her children all live in Botswana; her eldest son, Ian, is the country's fourth president.
This story caught the eye of Susan Williams, who went on to turn it into a masterfully researched book published in 2006. Colour Bar then came to the attention of the actor David Oyelowo, who became obsessed with making it into a film.
Director Amma Asante, who has Ghanaian heritage, was fascinated by the story and the inspiring figures at its centre.
"The tenacity he had to hang on to a white wife; to say: 'She's whom I'm in love with - if you want me, you have to have her'."
Oyelowo tells me about how he loved the book and was thrilled to get Asante on board as he had admired her film Belle.
"Something touched me very deeply," says Rosamund Pike. "Then I read the script and that feeling was borne out when I knew the story. We all aspire to love like this."
Back in Botswana, the premiere of A United Kingdom is a huge success. It is an extraordinarily uplifting film, beautiful to look at and moving without being slushy. During the screening there are shouts of joy when some of the audience recognise people they know on screen. At the end there is a standing ovation.
©The Daily Telegraph