Aert van der Neer, 'A River near a Town, by Moonlight', about 1645

Few people today experience a town or landscape lit only by moonlight. But in the seventeenth century, the ethereal, slightly cold quality of moonshine would have been entirely familiar – especially in winter, when the nights were long. It was only in 1670, about 25 years after this picture was painted in Amsterdam, that the city became the first city in Europe to install street lights (invented by a painter, Jan van der Heyden). Before that, if you went out anywhere at night, the only light you would have would have been from your own lantern or, when skies were clear, the moon.

Like winter landscapes, moonlit scenes like this appealed to a particular type of buyer, and there was enough demand for several artists to specialise in producing them. Aert van der Neer was one of the most successful and painted many examples of both varieties. In this picture the moon has appeared only briefly, breaking through a tiny gap in a cloudy sky. The cool light creates a contrast between the deep darkness in the shadowy outlines of the town and the highlights on the rooftops and gable ends. It reflects dully off the surface of the river and washes over the fields and farmsteads on the opposite bank.

The moon didn’t only provide an interesting way to light up a pleasing view, it also enabled people to keep working and moving. Here several fishing boats are returning to their moorings at the town quay. It’s likely that they are coming back to port just after dusk – the moon appearing on the horizon suggests it is either rising or setting – making the most of the extra visibility. It is hard for the human eye to perceive colour in low light, a fact reflected by van der Neer’s almost monochromatic palette. But there is just enough light for us to see that the pennants at the masthead of the two boats in the foreground on either side of the painting show the colours of the Dutch flag. The reddish hues in the sky and on the water are characteristic of his style. This lighting effect adds a hint of storminess, a dramatic mood which is heightened here by the remarkably turbulent sky.

Like most landscape painters of his time, van der Neer often either adapted real views to make them more aesthetically pleasing or created imaginary views designed to evoke a particular type of landscape. He also painted more than one version of some scenes. There is a painting by van der Neer very similar to this one, with boats in the same positions (City Art Gallery, Leeds). Van der Neer’s work is difficult to date with any precision, but this picture was probably painted in the mid-1640s.