For film producer and lead actor David Oyelowo, his six-year passion to bring the powerful true story of African King Seretse Khama to the U.S. has finally materialized with “A United Kingdom.”

This true-life romance between an English office clerk Rose (played by Rosamund Pike) and the future king of Botswana Seretse (played by David Oyelowo) is a stunning romantic story in the hands of director Amma Asante (“Belle”).

Based on extraordinary true events, the film is set in 1947 when the bright university student Seretse meets the young Ruth at a London dance. It was clear that they were perfectly matched, yet their proposed marriage was challenged by everyone near and dear to them. The situation grew from bad to worse when the British and South African governments decided to intervene in the name of “political” stability.

The uproar surrounding an African prince’s marriage to an Englishwoman, on the eve of South Africa enacting its evil apartheid laws that would eventually separate Blacks and whites, made their situation a political rally call for justice.

This film is essential viewing because love dared to challenge hate, and love won. Based on

Susan William’s book “Colour Bar,” this simple story about two people who just wanted a life together, in peace, directly influenced the outcome of British and African history.

As the heir to the kingdom of Bechuanaland (later Botswana) Seretse later becomes his country’s first democratically elected president. As a producer, Oyelowo, who memorably portrayed American leader Martin Luther King Jr. in “Selma,” has been carefully nurturing this film for more than six years. “A United Kingdom” is itself a political statement and relevant today. The evil of apartheid is rooted in the evil of exclusion, fed by fear. The facts, at the time, were the facts and the law. The English government controlled Bechuanaland as a British Protectorate and to that end, they sided with the morally bankrupt South African government, who made it clear that they would not accept a happy, mixed-marriage royal couple living on its border. If you dare take the temperature of America’s current political climate, it would show familiar telltale signs of the cancer that is intolerance.

The opposition sends Seretse into exile as Parliament and two prime ministers maneuver the African chessboard. Husband and wife, Seretse and Ruth, are bullied by many apparently “invincible” forces. Yet in the face of such hatred and threatening behavior, their peaceful but obstinate refusal to give up leads to the film’s rousing final scene.

This story is great filmmaking, and director Asante makes the end result look and feel effortless. Her eye for detail elevates every frame, and her gentle way with actors leaves them room to do what they do best, which is find the characters and move the story forward. She is one of the best storytellers working today, and the result as witnessed in “A United Kingdom” highlights this film as a modern masterpiece.