Karl Erich Danielsohn was born in 1920 in Berlin. His father was a well-known physician and his mother was a pianist. He was introduced to music early on in his life and the family attended the synagogue at Fasanenstrasse.
In 1936 Karl was taken by his mother to the UK, where he went to a Quaker school in Middlesbrough. He then moved in with his sister and her husband in Belsize Park and attended the Royal College of Music in 1938. He studied singing with Herman Gruenebaum, originally from Frankfurt.
In 1940 he joined the Pioneer Corps, where he stayed for three years. As soon as it became possible he joined the Royal Tank Regiment as a gunner and wireless operator. He was sent to the front (near Arnheim) and his tank was hit in 1944. He was injured, was taken to a hospital where he had an eye operation and then was sent to Fallingbostel prisoner of war camp, near the Lueneburg Heath.
Karl was liberated by the British Army in April 1945. After the war he worked as an opera singer for the Imperial Opera Company and Glyndebourne. He married Ruth Danson, a fellow refugee.