Émile Zola was a novelist, critic and political activist. In 1864 he met Gabrielle Alexandrine Meley who became his companion and, in 1870, his wife.
Zola worked as a clerk and journalist, and wrote short stories, beginning with Contes à Ninon (1864). After his first major novel, Thérèse Raquin (1867), he began a twenty volume series called Les Rougon-Macquart which traced the lives of three branches of the Rougon-Macquart family and in which he expounded his theories of naturalism. The series included Nana (1880), Germinal (1885), La Terre (1887), and La Bête humaine (1890). Whistler was familiar with his work although not closely involved with Zola himself.
On 13 January 1898, he supported the cause of Alfred Dreyfus (the French-Jewish army officer who was wrongly convicted of treason in 1894) with an open letter, 'J'accuse,' to the newspaper L'Aurore, denouncing the French general staff. He was tried for libel and sentenced to imprisonment, but escaped to England in 1899 and was able to return after Dreyfus had been pardoned the following year. However, the controversy affected him until his death.
Hemmings, F. W. J., The Life and Times of Émile Zola, London, 1977.