The elder of two sons of religious German-Jewish parents, Siegfried grew up in the city of Frankfurt. Upon completing his education, he became a certified public accountant in Frankfurt. In his free time he worked as a freelance music critic. While on a vacation in 1932 on the North Sea island of Norderney, he met Herta Katz, a young woman with whom he quickly fell in love.
1933-39: The Nazis had fired Siegfried from his government job because he was Jewish. Although his mother opposed the match, Siegfried proposed to Herta and she accepted. They married in June 1933. In 1934 they left for Amsterdam, where Siegfried found a job. Herta gave birth to a daughter and began a successful interior decorating business. Just before the outbreak of war in 1939, Siegfried's parents also moved to Amsterdam.
1940-44: In May 1940 the Germans occupied the Netherlands. Two years later the Wohlfarths were ordered to report to the train station, but went into hiding. In 1944 they heard on the BBC that the Germans had killed 2 million Jews in extermination camps and that the biggest camp was Auschwitz-Birkenau. When Herta and Siegfried were arrested and put on a train on September 3, 1944, Siegfried feared the worst. Determined not to let the Germans have more than his body, he tore up their money during the journey.
Siegfried was deported to Auschwitz, and later to the Stutthof concentration camp where he died on December 5, 1944.