Marcel Proust
Proust, Valentin Louis Georges Eugène Marcel (10 July 1871 – 18 November 1922) was a French novelist, critic, and essayist who wrote the monumental novel In Search of Lost Time (la recherche du temps perdu; with the previous English title translation of Remembrance of Things Past), which was originally published in seven volumes in French between 1913 and 1927.
Proust worked as a critic for the early portion of his adult life, as well as composing short stories and articles, before starting In Search of Lost Time at the age of 38, with each of the seven sections being published when they were completed. That carried on until after his death because he hadn't completed reviewing the final three by then. It's a tremendous undertaking, spanning 3,200 pages and containing almost 2,000 characters. The work stunned some of the most well-known literary figures of the day. It was dubbed "the best fiction to date" by Somerset Maugham, while Proust was dubbed the "greatest novelist of the twentieth century" by Graham Greene.