Perhaps the beating heart at the centre of the movement, Pissarro stuck with the Impressionists for longer than anyone else.
He was a mentor and force of unity, offering crucial encouragement and advice to young artists like Cèzanne, Gauguin, Seurat and Van Gogh.
The man received very little formal training, instead developing his style independently by producing countless countryside paintings.
He thrived on depicting dirt, leaves, molehills and unkempt environments and the day-to-day lives of French peasantry, often painting the same scenes at different times of day and lighting conditions.
In particular, take a look at the way he colours shadows. Instead of dark greys, blacks and muted muddy browns, Pissarro learnt to use colours of surrounding objects to inform the hues of his shadows.