When Winston Churchill became Prime Minister of the wartime coalition government in May 1940, he pledged his "blood, toil, tears and sweat" and within days of his appointment he was called upon to honour his promise. As the Low Countries fell to Adolf Hitler, and France was poised to follow suit, rescuing thousands of Allied servicemen from the beaches of Dunkirk was Churchill's top priority, as he proved beyond doubt that he was indeed the right man for the job.