Initially the focus was on high-quality textiles, with the manufacture of luxury goods being slowly added. After a fire in 1897, the building was extended and antiques, tapestries and carpets were added.In 1918, his son Otto Bernheimer took over, but Following Kristallnacht on 9–10 November 1938, which saw the huge plate glass windows of the Bernheimer-Haus smashed,he and his family were sent to Dachau concentration camp, and the Mexican government intervened, as he was the Mexican honorary consul in Munich. Hermann Göring, a Bernheimer client, did a deal whereby they bought his niece’s Venezuelan coffee plantation which was struggling, and were allowed to emigrate there, and also had to take Göring's aunt and her Jewish husband along, and support them until they died . After the war, Otto returned, and in 1948, moved into the art trade. In 1977, Otto's grandson Konrad Bernheimer born 30 August 1950 took over (his father committed suicide in Venezuela) and renamed the business Bernheimer Fine Old Masters, as the company was specializing in Old Master paintings from the 16th to 19th centuries. In 1987, the Bernheimer-Haus was sold by Konrad to pay his co-heirs. As well as being the chairman and owner of Bernheimer Fine Old Masters, Munich, he owns Colnaghi in London, founded in 1760, and the world's oldest gallery, which he bought in 2002.
He is a board member of The European Fine Art Foundation, and chairman of its fine art division, Pictura, since 2004. The Bernheimer sale of works of art from Burg Marquarstein at Sotheby's in London in November 2015 realised £2,371,000 and his carpet collection which was sold at Christie's London, February 14, 1996 was exceptional. His daughter Blanca Bernheimer has dealt in fine art photography since 2005.
