On becoming Prime Minister in 1940, Winston Churchill said that all his past life had been preparation for a moment of destiny, but no chapter had prepared him more than the First World War. In 1914 he had felt the same call of destiny and glory but would experience humiliation and disgrace.

In early 1916 he was an infantry officer serving in the trenches, where his battle to clear his name and regain war command began. The story of his fall and rise can be told largely in his own words, for Churchill confided all to his young wife in an intimate correspondence.