A United Kingdom

The headline says it all.

African Prince Plucks English Girl From Typing Pool.

Actually it says nothing of the sort. There are stories you think you know and when movies are based on them you can't be fished to fork out at the multiplex because you have made up your mind, based on the barest of details.

The story of Seretse Khama (David Oyelowo) and Ruth Williams (Rosamund Pike) is a case in point. As future king of a tiny impoverished country bordering on South Africa he is in London in 1947 studying to become a barrister. He meets Ruth at a dance. The rest is a romance worthy of Strictly.

There are hurdles along the way. There are barriers. Her father won't have anything to do with him. His uncle rejects the concept of a white queen and threatens civil unrest. The British government steps in to avoid embarrassment with diamond rich South Africa. The politics is ugly, cynical and destructive. Empiric morality is exposed yet again as a fraud because of "diplomatic necessity".

The film may exaggerate Seretse's courage and determination. Or not. Who knows? In the tradition of Virginia McKenna, Pike holds back the tears, straightens her back and gives an emotionally honest performance.

The same can be said of Oyelowo. This is the best thing he has done since playing Martin Luther King in Selma. In fact, surpasses it. As for Jack Davenport as the charm-soaked sleaze creep of a colonial official you need go no further in your distrust of public school ethics (or lack of).

Director Amma Asante and writer Guy Hibbert have taken an unusual love story that contains enough drama and prejudice to put the stereo back into type. And yet they don't. They do more.

History can be bent. History can be blurred. Here the tensions are taut and the feelings genuine.