Siegfried Adler was the firstborn son of Meier Adler (1864-1926), a schoolteacher born in Urspringen near Marktheidenfeld, working in Nuremberg, and his first wife Betty Rosenstein (1867-1917). The family initially lived at the Königshofen address Kellereigasse 81, before they moved to Roth by 1896. Siegfried Adler's brother Alfons was born in Roth on December 1, 1896, and emigrated to New York in 1938. Meier Adler married his second wife Karoline Rosenstein (1877-1930) in 1919.1
Adler took up his studies in Munich. He initially studied here from the winter semester of 1908/09 to the summer semester of 1910, and then again from the summer semester of 1912 to the summer semester of 1913.2 He was awarded a doctorate in medicine in 1919, and by early 1923, he received his license to practice medicine.
Siegfried Adler, who also spent time in Nuremberg (1924), Berlin (1931), and repeatedly in Munich (1925, 1926, 1927, 1930, 1931),3 moved from Munich to Bad Reichenhall in May 1922. He stayed at the Pension Rosenhof, Bahnhofsstraße 10, where he officially practiced medicine from 1929. He had previously had surgery hours at the Sanatorium Dr. Dresdner, Rinckstraße 7. He left the Pension Rosenhof in 1938 and found accommodation at the Sanatorium Dr. Dresdner, where he was registered from September 29, 1938.
Siegfried Adler, just like his colleague Gustav Ortenau, had been identified as a "Jewish doctor" in the Reichenhall spa list as of 1938. He moved to Krefeld-Uerdingen for unknown reasons on April 1, 1939, most likely as a result of discrimination and persecution.4 Here he was initially registered as "doctor (ret.)" at the address Westwall 80. Later he was given lodging at the so-called "Judenhaus" at Stadtgarten 13, but was able to move out again. His two subsequent addresses were Bismarckstraße 87, and Dreiköniginnenstraße 18 from 1941.5
Siegfried Adler was killed in the Shoah. The deportation began on April 22, 1942. Adler was taken to the Izbica ghetto near Lublin – a transit station on the way to the Belzec and Sobibor extermination camps – via Düsseldorf.6 He probably already perished in Izbica.