Dutch Schools
The Netherlands had two significant schools of painting which relate to Impressionism: the Hague School, and the Amsterdam School.
The Hague School roughly parallels the Barbizon School in France, and includes Jozef Israels (1824-1911) Anton Mauve (1838-1888), Albert Gerard Bilders (1838-1865) and Hendrik Willem Mesdag (1831-1915).
An excellent overview of the Hague School is given by Suijver R (2008) Reflection of Holland. The Best of the Hague School in the Rijksmuseum, Rijksmuseum. ISBN 978 90 868 9084 4.
The Amsterdam School was predominantly post-impressionist, and includes Isaac Israels (Jozef’s son, 1865-1934), George Hendrik Breitner (1857-1923) and Jan Toorop (1858-1928), who was a friend of James Ensor and a member of Les XX.
Johan Barthold Jongkind (1819-1891)
Born in Lattrop, the Netherlands, near the border with Germany, he trained at the Drawing Academy in the Hague from 1837, before moving to Montmartre in Paris in 1846 at the invitation of Eugène Isabey, who then became his next teacher.
During trips to Normandy and Brittany in 1847 he got to know several established painters, including Bouguereau and Cabanel. In 1848 his first painting was accepted by the Paris Salon, with a second in 1850.

He received critical acclaim, but did not enjoy commercial success, although one of his paintings was bought by the French State. In 1852, he again had success in the Salon, receiving a third class medal. In 1853 he met Courbet, Thomas Couture, and Nadar (who later hosted the first Impressionist Exhibition), and sold some oil paintings and watercolours at last. In the autumn, he visited London for a week.

He returned to the Netherlands in 1855, where he lived and worked in Rotterdam until 1860. In 1857, he returned to Paris briefly, dining with Courbet, Corot, and Millet.

He then went back to Paris, where his paintings showed early signs of loosening up and losing the ‘finished’ style of his early work. In 1860 an auction of works by other artists was held for Jongkind’s benefit in Paris, and he met his companion, Joséphine Borrhée-Fesser (1819-1891), also a painter, whose husband did not die until 1875.
In 1862 he went to Honfleur, where he met Sisley, Boudin, and Monet. He also started to produce etchings, mainly of Dutch themes.

During the 1860s he developed his full impressionist style, most prominently in his watercolours, which he generally preferred to oils.



In 1863 he exhibited three paintings in the first Salon des Refusés, but declined participation in the first Impressionist exhibition of 1874. He started to exhibit regularly in the Salon, with three paintings accepted in 1865, and two in each of the following four years. However in 1873 his submission was rejected, and he stopped trying to exhibit thereafter.





He first visited the Dauphiné region of France in 1873, returning repeatedly after that. In 1878 he bought a summer house in a town near Grenoble, living during the winter in Paris.


From 1881 he battled with increasingly severe bouts of depression and alcoholism. He died near Grenoble in 1891.
Jongkind anticipated the Impressionist style well in advance of those currently considered to be the core and leaders of the Impressionist movement. Many of its innovations – plein air paintings which appeared sketchy and impromptu, abundance of light and rich colour, unfinished appearance, visible brushstrokes – were first developed and brought together by Jongkind.
Indeed several of the Impressionists paid tribute to his influence on their style and technique. His watercolours in particular show a looseness and emphasis on mark-making which was seldom seen in the paintings of others until the early twentieth century, long after his death.
Although his decline in health during the 1880s and his preference for watercolour may have contributed to his loss into obscurity, I cannot understand why his works are not more widely shown, and better appreciated. If anyone led Impressionism during the 1860s and early 1870s, it was surely Jongkind.
References
Wikipedia
Association of the Friends of Jongkind
Sillevis J (2002) Jongkind, Aquarelles, Bibliothèque de l’Image. ISBN 978 2 914 66135 5. (An excellent in-depth account of his watercolours, extensively illustrated, and very reasonably priced. In French.)