Pierre-Henri de Valenciennes, 'Rome at Sunrise, from the Janiculum', about 1782-4

Pierre-Henri de Valenciennes is one of the most influential and important figures in the history of the landscape oil sketch, as an artist, teacher and writer. Almost one hundred years before the Impressionists, Valenciennes advocated painting in the open air. He even championed returning to the same subject at different times of day to capture changing light and atmospheric effects. One of his pupils, Achille Etna Michallon, was a teacher of Camille Corot, the leader of the Barbizon School of painters. The Impressionist Camille Pissarro recommended Valenciennes’s book Elémens de perspective pratique (1799) to Paul Cezanne in the 1880s. Valenciennes advised working in haste so as to ‘seize Nature as she is’. This maxim could easily be applied to artists such as Monet or Cezanne.

Valenciennes was born in Toulouse and trained there and in Paris. He first visited Italy in 1769 and returned in 1777. Apart from a brief trip back to Paris, he remained in Italy until about 1785. While he was there, he developed and refined his approach to landscape painting, then considered a lesser genre. For Valenciennes, a vital component in the creation of such paintings was the direct appreciation and understanding of nature, which were derived through close observation. He and his colleagues often made their sketches on small sheets of paper because they were easily portable. They used swift, expressive brushstrokes to rapidly capture what was before their eyes. These sketches were never intended to be shown in public. Instead, they were created as visual prompts for larger, more finished works produced in the studio.

Valenciennes made this sketch in Rome looking eastwards from the Janiculum Hill. The large building in the foreground is the hospice of San Michele a Ripa on the west bank of the Tiber. The tower behind it is the church of Sant’Alessio on the Aventine Hill. Above all of these are the clouds, at turns dark and light, black, grey and white. They move swiftly in front of a blue sky that breaks through in places, allowing sunlight to fall on the city.