When War broke out in September 1939, Neville Chamberlain was Prime Minster. Winston Churchill was appointed First Lord of the Admiralty, and was also a member of the War Cabinet.

On the 10th May 1940, in recognition of the fact that he had for many years seen Hitler as a threat, George VI invited Winston Churchill to Buckingham Palace, and asked him to form a government and become Prime Minster.

In his first speech to the House of Commons after becoming Prime Minister, on the 10th May 1940, Churchill set out the truth as he saw it.

Churchill was a man whose hour had come. He had been irrelevant in politics in the 1920s and 30s, but cometh the hour, cometh the man, and Churchill became the great war leader.

Churchill offered no magic bullets, no miracle solutions, and no false hope. Instead, as he himself said on 13th May, shortly after forming his government:

I would say to the House, as I said to those who have joined this government: "I have nothing to offer but blood, toil, tears and sweat."

Perversely, this seemed to cheer the population up a bit. Someone was telling it to them as it was, and that didn't seem all bad.

Speech in the House of Commons, 13th June 1940:

...the Battle of France is over. I expect that the Battle of Britain is about to begin. Upon this battle depends the survival of Christian civilization. Upon it depends our own British life, and the long continuity of our institutions and our Empire. The whole fury and might of the enemy must very soon be turned on us.

Hitler knows that he will have to break us in this Island or lose the war. If we can stand up to him, all Europe may be freed and the life of the world may move forward into broad, sunlit uplands.

But if we fail, then the whole world, including the United States, including all that we have known and cared for, will sink into the abyss of a new Dark Age made more sinister, and perhaps more protracted, by the lights of perverted science.

Let us therefore brace ourselves to our duties, and so bear ourselves, that if the British Empire and its Commonwealth last for a thousand years, men will still say, "This was their finest hour.

And on 4th June 1940:

We shall go on to the end, we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island, whatever the cost may be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender....