As I said, this is a thorough book. It is also strange -to me at least. Churchill is probably as close to a beatified politician (in England at lease) as it is possible to get (though I suspect that William Wilberforce might push him close if people were more aware of him). I'm not sure why, but I expected this to borne out by this book. I'm not sure it was.
The book is divided into 3 parts. The first 40% deals with his pre-war days. The next 40% deals with World War II. The last 20% looks at what happened after he lost the 1945 election.
The first part presents him as someone who has little impulse control. He didn't think he'd live all that long (a family history of death at a comparatively young age was to blame for this), and as a consequence he seems to have wanted to live his life to the full before entering parliament.
The two war phases of his life were the most interesting parts of the book. I was surprised quite how much he screwed up during World War I. I know this is written with the benefit of hindsitght, but I found it quite stark when Jenkins was describing Churchill as making "statesmenlike decisions" in World War II.
The last part of the book was most depressing. Churchill was clearly past his best during many periods of it, and though he made many strong speeches (the "Iron Curtain" speech for example), I got the feeling he was in a downward spiral during this stage, even if he made several accurate predictions about the future.
At the end of the book, Jenkins claims that he was a great leader. I have no doubt that his was. I didn't get a sense from the book that there was anyone else who could do what he did. But I'm not sure he was a great man. As an example, he drank like a fish, and he tended to get locked onto some palpably daft ideas (like refusing to grant Indian independence), which made you want to yell at him on occasions, and I found that rather sad to be honest.
All this having been said, I think that the fact that we saw the "whole Churchill" is a strength of the book. We get to see Churchill the man as a rounded individual, warts and all, and I think we're better off for knowing that about him.