​For well over a century it was a family secret: Vincent van Gogh’s sister-in-law, Jo Bonger, had a short relationship with the Dutch Impressionist painter Isaac Israëls. Israëls, Portrait of Jo van Gogh-Bonger (1895) and Self-portrait wearing a black Hat (1894-98) Van Gogh Museum, Amsterdam (Vincent van Gogh Foundation)​Captivated by Vincent: The Intimate Friendship of Jo van Gogh-Bonger and Isaac Israëls (until 25 January 2026) is not just about the relationship, but equally importantly it covers its impact of Van Gogh's art on Israëls. ​Isaac Israëls (1865–1934), the son of the distinguished artist Jozef Israëls (1824-1911), first met Bonger briefly in September 1889 through her newly-married husband Theo van Gogh, Vincent’s brother. In the background Israëls added a fuzzy picture, which appears to represent the strong blue sky of Van Gogh’s The Yellow House. Israëls, Portrait of Jo van Gogh-Bonger (1926), with the deep blue sky of Van Gogh’s The Yellow House in the background Van Gogh Museum, Amsterdam (Vincent van Gogh Foundation)Israëls died in 1934.