He is also known as Ernst Dorian and was an Austrian actor. He was born in Prague, Austria-Hungary, now in the Czech Republic in 1890 to Ludwig Kraus and Louise. He married Anuschka Fushsin in 1922. He died in Berlin in March 1969, from a heart attack.
He grew up in Prague and did his high school from there. He was a good tennis player as listed in the Austro-Hungarian tennis list, where he ranked number seven. After he completed his high school, he served in the army for a while.
In 1914, he for the first time performed on stage for Berthhold Viertel at the People’s Theatre in Vienna. After Prague, Ernst was hired by Edgar Licho for the Albert Theatre in Dresden in 1916. Here he acted in The Robbers and Spring Awakening. He established himself as an expressionist actor after his work in The Son, which premiered in October 1916. After this he did around 42 silent films, and in 1917 he shifted to Volksbü̈̈̈̈̈̈̈̈̈̈hne in Berlin and continued his career in acting. From 1916 to 1917 he acted in various plays such as Hamburg, Munich and Vienna and a tour to South America.
In 1933, he left Germany due to the Nazi anti-Semitism. He returned to Vienna and Prague and Zurich, Brussels (1936) and London gave many guest performances during this time. In 1938 he immigrated to New York City and a year later he got American citizenship, during this time he briefly performed on Broadway. In 1939 he moved to Hollywood and from 1942 onwards he started appearing in Hollywood movies, primarily as a Nazis or German officer. This was ironical considering that he had left Germany for the reason that he had Jewish roots. He is most commonly known to the English speaking audience as the Baron Kurtz in 1949 film 'Noir', 'The Third Man'.
In 1946, he spent some time in Buenos Aires and in 1947 he went to Paris after which he went back to Vienna, where he became a member of the Burgtheater. In 1948, he appeared at the National Theatre in 'The Helpers of God' about Henri Dunant, the founder of Red Cross. In 1951, after the war he moved to Berlin. In Berlin, he appeared in Schiller and Schlossparktheater.
In 1948, he received the Volpi Cup in the Venice International Film Festival, as Best Actor for his performance in Der Prozeβ. He gained recognition for his performances in 'Nathan the Wise' as Gotthold and as Shylock in 'The Merchant of Venice'. In 1964, he got an Honorary Award for his “Outstanding individual contribution to the German Films over the years”. He played 'Nathan the wise' for more than 2000 performances and travelled throughout Europe for this. He last performed in the Junge Theater in 'Nathan the Wise'. In 1973 the same theatre was renamed Ernst Deustsch Theatre in Hamburg.