It is more than a crowd, it is an organised mass of workers walking towards you at eye level, led by a trio, including a woman carrying her child. There are no banners or work tools but it feels like an organised march of some sort. Behind the trio, there are rows of workers filling nearly the horizontal line of half the painting. The colours are warm shades of brown, grey, pink, green and beige. Everyone is walking into the bright sunlight behind the viewer. Their hats shield them from the bright light. In the background, there is a rich, green countryside.

These are rural wage workers whom Pellizza had seen marching in his local area near Alessandria in the northern region of Piedmont. The artist said they are “men, women, old people, babies, all hungry who are coming to demand their rights”. He also said the question of social inequality was on the agenda and “art must not be outside this movement.”

He does not paint them in a way that shows great deprivation or desperation. Instead, there is quiet dignity and power. There almost a classical pre-modern representation of the people who are placed under an arch. It could be a painting by Michaelangelo or Giotto from the early renaissance. Pellizza was attached to the divisionismo school which followed the recent developments in the science of colours. Dots of colour were carefully put together to give a particular chromatic effect. (cf. Seurat’s Bathers at Asnieres, in the National Gallery). As a result, the symbolic sense of the workers as a class rather than as distinct individuals is reinforced. Pellizza as an ethical socialist wanted to show the new, growing workers movement marching from the end of the 19th century into the light of progress into the 20th century. The class is presented as the universal subject that goes forward to liberate humanity.

First shown in the Quadrienniale exhibition in Turin in 1902 it made little critical impact. Its success grew out of its use on posters and postcards by socialist organisations. Like some of William Morris or Walter Crane’s pictures, this was art that became successful because of popular involvement. It was certainly one of the first examples of art in Italy being used in political campaigns. It became a lot less visible in the fascist period after 1922 and it was taken out of display. After the Liberation in the 50s and 60s, it again became known but it was its use by Bertolucci, in posters for his great film Novecento in 1976, which popularised it again with the generations who radicalised after the 1969 hot autumn. Today it has even become a meme where other personalities and characters have been transposed onto the iconic work. I have seen one with all the great Neapolitan celebrities like Sophia Loren, Toto, Maradona etc…

The picture’s simplicity, humanity and optimism hit you straight away when you walk into the 20th-century museum just opposite the cathedral in Milan. It is a big canvass – 283X550 – as a big history painting of this sort demands. The picture is one of the best selling posters there. The name Fourth Estate refers back to the French Revolution when the urban and rural works were described in this way.

One hundred years ago the Communist Party in Italy was founded. It led to the resistance to the Nazis and became a mass party of 5 million members. Today its wretched offspring, the Democratic Party, bows and scraps in honour of an EU banker who leads a government they have joined. What a retreat from the optimistic birth of our movement expressed in this picture. It is as if the bright sunlight of progress has been snuffed out. Other radical forces will have to take up the march started by these workers.

For Pellizza too it all ended badly. His wife, who was the model for the women in the leading trio, died in childbirth in 1907. His art was not selling. He hung himself in the same year.