The Splendid and the Vile by Erik Larson was an excellent read about Winston Churchill and focuses on his opening year as U.K. Prime Minister. Hitler invaded Holland on Churchill's first day in office, May 10, 1940, and the Dunkirk evacuation ordered May 26.
The book provided a view into how Churchill during this crucial year both held the country together and convinced Franklin Roosevelt to offer much needed aid to the United Kingdom while it unclear if the United States would play a role in the war. Churchill had to manage a fine line with Roosevelt as well as the American public, showing that Britain needed help, but also that the aid wouldn’t be in vain and they could overcome the German bombing campaign. The first air raid on London was September 7, 1940 and last May 10, 1941, with that final attack killing 1,436 people. Over the course of this period, there was a stretch that bombing went on for 57 straight nights, and the Blitz killed some 45,000 British people, 29,000 in London.
Churchill was demanding of the people who worked for him, both in terms of hours required and mandating an economy of words in reports, people having brevity and getting directly to the point. He also understand gestures, having anti-aircraft guns positioned in London and firing skyward during raids. Even though the chance of doing damage were minimal, it showed Brits that they were fighting back. 1940 was a US Presidential election year and Roosevelt won reelection with his opponent Wendell Willkie in the months just prior to the election running as an isolationist. The Lend-Lease Act was proposed by Roosevelt in December 1940 and in early 1941, he sent the first of two emissaries to the U.K. to assess Churchill and the state of things against the Nazis. Churchill would later describe Harry Hopkins and then Averell Harriman as key allies in making his case to Roosevelt.
It’s detailed in the book how a reason the feared ground invasion of the U.K. never came was that Germany never took control of the air, with the British Air Force fighting back valiantly against the Luftwaffe headed by Hermann Goring. Germany then diverted attention to invading the Soviet Union, fighting the two-front war that Hitler had said shouldn’t be done, and in December 1941 Russia was getting bogged down with its Russia invasion, and then came Pearl Harbor on December 7. The US declared war on Japan the next day and on December 11, Germany declared war on the US. The war in Europe ended May 8, 1945, a week after Hitler committed suicide, and the two atomic bombs were dropped on Japan in August 1945.