The Ernst Sandau photography studio was founded by the Swedish Ernst Sigfrid PETTERSSON (1880-1918) at Unter den Linden 19 in Berlin. It will be taken over after the first world war by the German photographer Suse BYK (1884-1943) until its closure in 1938. Ernst Sigfrid PETTERSSON was born in Sweden, in Linköping, January 15, 1880. He began a career as a civil engineer in Stockholm. At the end of the 1880s, he opened a shop at 1 Österlånggatan Street, where he also offered photography. It was at this time that he took the name Ernst SANDAU. Around 1905, he arrived in Berlin where he established himself as a portrait painter. In 1909 he married Cornelia von SCHMOLLER, the daughter of Gustav von SCHMOLLER a prominent German economist and social scientist. At that time he opened his studio in the famous Unter den Linden 19 in Berlin. On May 24, 1913, the marriage of Victoria-Louise of Prussia and Ernest-Auguste of Brunswick, Prince of Hanover gave him a prestigious clientele since the royal and imperial courts came to Berlin like Queen Mary, Georges V or Nicolas II. portrayed by SANDAU. His studio becomes a must for Berlin high society. Mobilized during the war, his wife cheats on him with cadiologist Pierre Schrumpf-Pierron. He divorced on January 17, 1916. SANDAU died May 31, 1918 of tuberculosis in the Grünewald sanatorium. His son Ernst Sigfrid junior being too young, the studio was bought by the photographer Suse BYK (1884-1943). Suse BYK was born in Berlin in 1884 into a Jewish family of Ukrainian origin. His father is Dr. Siegmund BYK (1856–1936). Suse does her apprenticeship as a photographer at Lette 's school. In 1910, she joined the Berlin Photographer Association. The same year, she resides her photo studio at her private address on Kurfürstendamm 14/15. After the death of Ernst SANDAU in 1918, she took over the workshop, keeping the name in order to benefit from its reputation. Suse BYK marries journalist and writer Hellmuth FALKENFELD (She is listed as Suse Falkenfeld in 1931 in the Jewish Address Book for Greater Berlin). Under her leadership and throughout the period of "die Goldenen Zwanziger" a large number of artists and scientists from Berlin passed by her lens. She also carried out commissions for fashion magazines and also worked as a theater and film photographer . After the handover of power to the National Socialists in 1933, BYK continued to work under conditions of anti-Semitism, only to give up in 1938. She tried to sell the company before emigrating to the United States, but without success. Finaly, Liselotte STRELOW, which had been formed by BYK, will buy the company for the aryanization price (half price of the sum requested by BYK). On October 1, 1938, STRELOW reopened under its own name while in July 1939, BYK and Sandau studio was struck off the commercial register. The studio and the archived photos were destroyed during the war. Ernst Sigfrid SANDAU junior also became a photographer. He signed with his own name, but without mentioning an address. He notably produced many portraits of personalities of the Third Reich.