Hans Sonnenberg was born 1928 in Makassar, Indonesia. His family moved to the Netherlands in 1931, and acquired a house in Rotterdam in 1935. His mother took him to museums as a child and decorated the house with antiques and paintings by Isaac Israëls and Lizzy Ansingh, among others. As a result, Sonnenberg became fascinated by art at an early age. Later, during his military service at Oirschot, he regularly visited the Van Abbemuseum in Eindhoven and at weekends he spent much of his time in Kunstcentrum ’t Venster (The Window Art Centre) in Rotterdam.
After completing his military service, Sonnenberg worked as a shipbroker in Rotterdam’s harbour. Alongside his office job, he was very active in the art societies of the Schielandshuis and the Rotterdamsche Kunstkring. In 1954, he organised his first exhibition of Rotterdam-based artists around the theme of Rotterdam’s harbour. Sonnenberg was also well informed about developments in the international art world, and brought many foreign artists, including Piero Manzoni, to the attention of artist and gallerists in Rotterdam.
To give modern Dutch artists a larger platform, in 1959 Sonnenberg decided to establish the artists’ group Zero. He took charge of the group’s official functions and organised its exhibitions. In 1960, he received an offer to manage a new gallery in The Hague. He saw it as an excellent opportunity to give Zero a regular venue, and called the gallery ‘Eroz’, Zero spelled backwards.
In 1962 Sonnenberg became the manager of the R.K.K. gallery, which he immediately renamed Galerie Delta. Sonnenberg was given free rein over the gallery’s programme and was not financially dependent on sales for his income. This freedom allowed him to combine his interest in international developments with his dedication to local artists. He maintained close associations with Rotterdam-based artists, and was a fervent champion of Dutch art, both at home and abroad. His successful programming policy at the gallery earned him the nickname, Mr Delta.
Hans Sonnenberg played a crucial role in Rotterdam’s art scene, giving many emerging artists an opportunity to show and sell their works. He was also a loyal friend of Museum Boijmans Van Beuningen. In 2012, Sonnenberg gifted fifteen paintings to the museum, allowing the curators to make a personal selection from his private collection. Through this generous gift, the museum was able to add works by world-famous artists such as Jean-Michel Basquiat and David Hockney to the collection. That same year, the museum organised the exhibition Mister Delta, accompanied by a Boijmans Study with the same title. In the exhibition, the works Sonnenberg gifted to the museum were supplemented with purchases the museum had made over the years at Galerie Delta and various works from Sonnenberg’s private collection. The exhibition was a tribute to Sonnenberg and his enormous contribution to the development of modern art in Rotterdam. After his death in 2017 the museum receives several other artworks from his legacy, among them are works from Paul Beckman, A.R. Penck and Milan Kunc.