Werner Haase was born in Koethen, Saxony-Anhalt, German Empire on 2 August 1900. He served in the Imperial German Army during World War I, and he became a surgeon after obtaining his doctorate in 1924. He joined the Nazi Party in 1933 while working as a ship doctor, and he joined the surgery clinic of Berlin University. Karl Brandt promoted Haase to serve as Adolf Hitler's deputy personal physician, and he joined the SS in 1934. Hitler had a high opinion of him, sending him a telegram on 2 August 1943 to send his "heartfelt congratulations" on his birthday. In April 1945, Haase, Ernst-Gunther Schenck, and Erna Flegel worked to save the lives of many wounded German soldiers and civilians at an emergency casualty station in Berlin during the Battle of Berlin, and Haase himself fell ill with tuberculosis. When Hitler asked Haase for a recommended method of suicide, Haase told him to bite on a cyanide capsule and then shoot himself in the head. On 2 May 1945, Haase was taken prisoner by the Red Army, and he died in the Butyrka prison of Moscow while in Soviet captivity.