By 1868, when Millet was in his mid-fifties, his social realism had been toned down, but he still showed himself capable of the unexpected, such as his pastel painting of Dandelions (1867-68). He had also received his most valuable commission, for a series of paintings of the four seasons.
With the rise of Impressionism over the final years of his life, Millet painted some extraordinary works exploring transient and unusual effects of light. His career was inevitably interrupted by the Franco-Prussian War: Millet moved with his wife and large family back to the area of his birth, near Gréville, for much of 1870-71.

One of his commissioned series, Spring (1868-73) is less about the blossom on the trees, or the mysterious figure in the distance, and more about its startling light: not just the double rainbow shown at the upper left, but the fleeting sunshine which floods the central part of the view. From the crops and seasonal flowers in the foreground to the inky black shower-clouds in the sky, this is a perfect summary of Spring in the countryside. It is now a countryside devoid of Millet’s toiling peasants.

Some of his depictions of life in the country were becoming worryingly sentimental too. La becquée (c 1870) is an ingenious and amusing painting, but a far cry from his previous work. A mother sits on a tiny stool, feeding three young daughters from a bowl which she cradles on her knee. As the food is offered to the middle girl on a wooden spoon, the child opens her mouth like a young chick in a bird’s nest.
Millet includes some other references to the theme: in the background a chicken walks towards the group, and two others are seen in the yard behind. On the ground close to the mother, a small wicker basket lies overturned on the ground, its contents suggestive of the eggs in a bird’s nest.
The family is obviously still part of the rural poor, but the social message is now buried in its gentle humour and sentimentality.

A Norman Milkmaid at Gréville (1871) is more in keeping with his message: caught in the (dawn?) twilight on her way to/from work, a grubby and exhausted young milkmaid is carrying a tatty old earthenware milkpot on her shoulder. Behind her the sky shows wonderfully fleeting light effects.
During these later years in his life, Millet’s health started to deteriorate. This did not stop him from painting, though.

Millet had also painted occasional landscapes, particularly of the coastline near his home village. The Cliffs of Gréville (1871) is a fine pastel depiction which surprises by its unusual scaling and distance effects. At first sight, the more distant clifftop seems quite far away, but the man recumbent on the skyline establishes that it is in fact quite close to the viewer. The white foam of the waves down below is shown very gesturally.

In The Gust of Wind (1871-73), Millet explores another transient effect, that of a severe storm. Its lone and distant figure is being blown almost double, as he is nearly struck by a large branch torn from the tree to the left. Indeed, that tree itself is being uprooted, and its leaves pepper the storm sky at dawn.

Calling the Cows Home (c 1872) is another depiction of fleeting effects of light in the countryside. Its lone figure of the herdsman has receded into the distance, though, and it is pictorial rather than bearing any social message. I am not sure how complete this painting is either: the cow in the foreground is clearly seen in its original drawn outline. Although Millet left some of his drawings in this style, this is claimed to have been painted in oils, which would imply that he did not finish painting that cow.

The Shepherd (1872-74), drawn in Conté crayon, is another puzzle. It would appear to be a preparatory drawing for Millet’s Shepherd Tending His Flock which has been claimed to date from around 1862, a decade earlier.
In the last couple of years of his life, Millet painted two exceptional works which look back at his career, and forward to the end of the century.

Millet’s Haystacks: Autumn (c 1874) contains a retrospective of many of his best paintings. The harvest has been gathered, and three huge haystacks dominate the canvas; they are painted in the distinctive style of all his haystacks. At the foot of one of them, a shepherd leans on his staff, resting from his labours as his flock gleans among the stubble.
The field opens to the plain around Barbizon, the open countryside where so many of Millet’s paintings had been made. Above, the sky is full of swirling birds, lit white against the purple-grey cloud of a building shower.

Quite unlike any of his previous paintings, Bird’s-Nesters (1874) shows country people clubbing small birds to bring them to the ground, where a couple are bent so low against the ground that they are almost resting on it, scrabbling to pick the stunned birds up and take them away as food. The man jumping up at the right is holding a burning hay brand to attract the birds to the clubs.
The light of the brand, birds, and branches of trees result in a unique broken effect, as if this were taking place in the middle of a violent electrical storm. This painting is breathtakingly innovative, and an intense visual experience like nothing I have seen in other nineteenth century art.
Millet died at Barbizon in early 1875, shortly after he and his wife had at long last been married in a church.
References
Wikipedia.
L’Atelier de Jean-François Millet, a private museum.
Sensier’s biography of Millet in English, and in French.
Lepoittevin, Lucien, and Lacambre, Geneviève (eds) (2002) Jean-François Millet, Au-delà de l’Angelus, Éditions de Monza. ISBN 978 2 908 07193 1. (In French.)