Claude Monet's first solo exhibition in London was organized by Theo van Gogh, the brother of Vincent, according to a letter published for the first time in a new book on the Impressionist's correspondence. The detail appears in Claude Monet: A Life in Letters, issued by Thames & Hudson last week, and was highlighted by The Art Newspaper's Van Gogh specialist Martin Bailey.

The letter was written by Monet on 3 May 1889 to Alice Hoschede, his companion and later wife. In it, Monet reports on the London show that Theo, manager of the Boussod and Valadon gallery on the Boulevard Montmartre in Paris, had arranged for him. Monet told Hoschede that nothing had sold, but added that the exhibition had been warmly received by the public and praised by the English press, with critics hailing him as the "true hero of art" of the moment.

Bailey traced the original review to The Echo, a London evening newspaper, which on 15 April 1889 opened its notice with the line that "M. Claude Monet is the art-hero of the hour." Theo had known Monet since the mid-1880s and had begun selling his work in earnest in 1887. In February 1889 he mounted a Monet exhibition at his Paris gallery, then swiftly shipped a larger group of paintings to the firm's London branch at 116-117 New Bond Street.

The discovery recasts a small but telling episode in the Impressionist market. Theo van Gogh, better remembered as Vincent's dealer-brother and financial lifeline, was in fact one of the shrewdest commercial operators of his generation, and his London initiative gave Monet a critical foothold in Britain at a moment when the French avant-garde was still fighting for British acceptance.