The meaning and origin of the expression: The darkest hour

The darkest hour

What's the origin of the phrase 'The darkest hour'?

The expression 'the darkest hour' came into widespread use in early 19th century England. However, the usage of the phrase that has more recently become popular originated well before that, in the proverb 'the darkest hour is just before the dawn'. A version of the proverb was recorded by Thomas Fuller in A Pisgah-Sight Of Palestine And The Confines Thereof, 1650:

It is always darkest just before the Day dawneth.

'The Darkest Hour' is the title of a 2017 WWII film drama starring Gary Oldman as Winston Churchill. The film alludes to the apparently imminent defeat of the British as their 'darkest hour' and, although this might sound like a Churchillian turn of phrase there is no record of him having coined it in any of his copiously recorded speeches or writings. It was used in a letter to Churchill from Clement Attlee, who became the British Prime Minister shortly before the Japanese surrender in 1945. Attlee gave Churchill due credit as the UK's war leader:

"I feel that the probability of the surrender of our last enemy is so great that I must, at once, offer to you, our leader from the darkest hours through so many anxious days, my congratulations on this crowning result of your work."

It can certainly be said that, as far as Britain was concerned, 'the darkest hour was just before the dawn'. Churchill referred to the war years of the British people as their 'finest hour:

...If the British Empire and its Commonwealth last for a thousand years, men will still say, "This was their finest hour."