Ernst Hanfstaengel, the son of a wealthy publisher, was born in Munich, Germany, on 2nd February, 1887. He had an American mother and was sent to Harvard University where he graduated in 1909.

Hanfstaengel remained in the United States during the First World War and did not return to Germany until 1919. After hearing Adolf Hitler at a meeting he joined the National Socialist German Workers Party (NSDAP). He became one of Hitler's earliest financial supporters and provided the money to buy the Volkische Beobachter.

Hanfstaengel took part in the Beer Hall Putsch in 1923 and afterwards hid Hitler in one of his country homes. The two men remained close and in 1931 Hanfstaengel was appointed Foreign Press Chief of the Nazi Party. Over the next few years he tried to use his contacts to improve the image of Hitler in other countries.

Hanfstaengel had a dispute with Joseph Goebbels and was informed in March 1937 he was in danger of being murdered. He fled to United States where he was employed by Franklin D. Roosevelt as a "political and psychological warfare adviser in the war against Germany."

After the Second World War Hanfstaengel returned to Germany where he published his book, Hitler: The Missing Years (1957). Ernst Hanfstaengel died in Munich on 6th November, 1975.