Sisley applied for French citizenship in 1898 and was refused. He applied again. Illness intervened. He died a British citizen in France, having never held French nationality, despite living there for almost his entire adult life.

He was born in Paris in 1839 to English parents. His father William ran a luxury goods import-export business. At eighteen, Sisley was sent to London to study commerce. He came back wanting to paint. He studied alongside Monet, Renoir, and Bazille at Gleyre's studio in the early 1860s.

He was the most landscape-committed of the Impressionists: he painted almost nothing else. No portraits, no cafe scenes, no modern life. His father's business collapsed during the Franco-Prussian War. Sisley had been financially comfortable until then; after 1870, he lived in poverty for the rest of his life. In 1876 he painted a series of six canvases of the catastrophic Seine flooding at Port-Marly: moody skies, planks laid as walkways, skiffs serving as ferries. They are among his finest works.

He died of throat cancer in 1899 at Moret-sur-Loing, aged fifty-nine. His partner Eugenie Lescouezec had died a few months earlier. Prices for his paintings increased almost immediately after his death.