Erik Larson uses familiar sources, but also many diaries not only from notable people, but also from not so notable people and both sides of the conflict.
This one man is responsible for a lot of what we have today demonstrating how to stand up to fascism. We forget the hardships the Brits put up with that mock our complaints about Covid-19 lockdowns.
Much of Europe had already submitted to Germany and it seemed France was on the run. British troops were in retreat. He was greeted with disaster after disaster, but kept his cool and did what he could to improve the situation.
Hitler could not understand the stubbornness of the British, but he did have some restraints. He didn't want to be known for demolishing London. He feared the navy, more than the RAF. At one stage he decided he had to attack Russia before America entered the war. Although it seemed the Germans had a big edge on organization and scientific modern warfare, the British developed their own scientific and intelligence breakthroughs.
Lord Beaverbrook, born in Canada was a key person in Churchill's strategy. He is the one who dramatically increased aircraft production and despite poor health took on tank production at a critical time. He was also a steady comrade in arms. Churchill had a way of finding the right people and motivating them.
The Battle of Britain and the blitzkreig put terror to everyone, not only in London, but also in many outlying population centres. Churchill didn't scurry and hide, but actually watched the fireworks. Shelters were often put together haphazardly, but slowly their safety and convenience was improved with credit to Clementine Churchill. German pilots older and more experienced from the Spanish Civil War and the start of World War II, but the British were courageous and resourceful. Radar, intelligence and aircraft production closed the gap.
The Americans were seen as the life saver and Churchill spent a lot of effort courting them. The attitude of the American public was of isolation. Congress would have to agree to war and even to financial aid. Most Americans sympathized, but not willing to go as far as Franklin Roosevelt. Roosevelt sent over Harry Hopkins and then Averill Harriman as his personal representatives and both were helpful. As Britain became more desperate Roosevelt was able to fine-tune legislation to lend material, ship needed goods. At one point the British Ambassador to America died in office and it was decided to send Lord Halifax (against his will) in his place. It took the Japanese attack at Pearl Harbour in December of 1941for the U.S. to declare war, but they quickly included Germany with their declaration against Japan.
While bombs were falling life continued. Illicit and licit, successful and not romances, were noted from diaries. One critical staff, John Colville pursued his love and only had an unsatisfactory platonic relationship. There were other temptations for him, but he stuck with his true love (at least for awhile). He wanted to resign to avoid nearness to a hopeless case, but Churchill refused. Eventually he entered the armed forces, finally in combat and returned to greater respect and married someone else.
Erik does end his narrative in May 1941 with the blitz ended May 11th, There are a few loose ends that he ties up. One interesting one is Churchill's daughter Mary became an anti-aircraft gunner. Another one was about the affair of Averill Harriman and Pamela Churchill. both married to other people. Averill had been sent to Moscow and their romance wound down. Averill stayed with his wife up to her death. Pamela married Leland Hayward until his death. After many events the two met in a private dinner hosted by Katherine Graham, owner of the Washington Post and eight weeks later they married. The marriage lasted until Harriman's death in 1986.
Another readable book by Erik Larson is "The Devil in the White City" http://www.therealjohndavidson.com/2018/04/the-devil-in-white-city.html