Philips Wouwerman, 'Cavalry making a Sortie from a Fort on a Hill', 1646

Philips Wouwerman has captured the violence and cruelty of battle as it was in seventeenth-century Europe, when Holland was closely involved in the wars that raged across the continent. Most of the scene is in shadow, with details picked out in one or two flashes of colour: a horse’s rump, a red jacket, a helmet, a fallen battle flag. The cold, brilliant light is more like cannon fire than sunlight.

Wouwerman has also evoked the terrible sounds of battle and the claustrophobia, with shoving, slashing, thrusting arms and bodies entangled till they seem almost wedged in, unable to turn or to escape. The strong diagonal of the fight descending the hillside adds to the instability of it all. Not just the armies are at peril: the castle on top of the cliff and a second a short way behind it look as if they might keel over and tumble at any minute. The gaping mouth of the castle and the broken spikes of the blackened fence on the ridge of the hill seem to add to the terror of the event.

Overhead, billowing grey smoke from cannon and burning buildings rises up and merges with grey clouds, making the cliffs beyond the battle seem almost insubstantial, and the tiny figures standing on them like ghosts. A single horseman gallops away from the combat towards the sea.

This picture is one of the largest battle paintings that Wouwerman ever made and is one of his few dated works. We know it was painted in 1646, and like his other battle scenes, it’s entirely imaginary. Although he makes a feature of a flag carried by a horseman silhouetted against the sky, it is torn and unrecognisable. The other flags, the uniforms and the buildings are inventions. In another painting, Cavalry attacking Infantry, we see what might be a blue Swedish flag – Sweden was at war with Poland during the time of the painting – but it’s far from conclusive and probably fictitious like the others.

The realism comes from the dramatic composition and eerie lighting, the depiction of bodies and faces, and, perhaps above all, the portrayal of the animals. Wouwerman was known for his ability to paint horses, and he has included his signature white horse in this picture. You can find it in several other of his works in the National Gallery, including A Horse being Shod outside a Village Smithy and The Interior of a Stable – both show these elegant creatures in happier, more wholesome surroundings.