Though the scene is strange and almost surreal, it is the only depiction of the event known to have been painted by an eyewitness. The large painting, measuring 3ft 4in x 5ft 4in (1 x 1.64m), is the centrepiece of the exhibition Holding the Line, which art dealer Andrew Sim stages at the fair.
Ahead of the event, Sim has produced a short video of him discussing the composition with Dr Jonathan Black, a fellow of the Royal Historical Society, senior research fellow at Kingston University and authority on British war art.
“It’s quite unusual that you have a quite competent painter who was actually on the spot,” Black says. “All the other images of Dunkirk that I have seen by the official war artists are from the point of view of the sea looking towards the land, usually from the perspective of the little boats or a destroyer picking up troops rather than the other way around.”
The painting was sold at a Lindsay Burns auction in Perth last year. The local vendor had bought it at auction when it was sold by the Institute of Army Education. Prior to that, Winston Churchill, Spencer-Churchill’s uncle, had kept the painting at his home, Chartwell.
Sim also features a posthumous portrait of one of the Great Escapers which has never been seen in public and a collection of pictures by a silent film director turned ARP warden.
The British Art Fair runs from September 20-23 at the Saatchi Gallery in Chelsea and hosts around 50 dealers.