Way back when I still lived in Chicago, William Manchester wrote the first two volumes of a huge biography of Winston Churchill. Volume two ended (IIRC) just as Churchill was asked to form a government during World War II.
Then nothing. For decades.
Apparently, the author was declining, and though he spent much of his later years gathering notes and information to use in the last installment, by the time he had all he felt he needed, he could no longer write. Sad.
However, he asked that a particular writer take up the material and finish the project, and the fellow did. So, more than a year ago, I think, the final book was published, and I grabbed a copy as soon as I heard about it.
The Last Lion: Winston Spencer Churchill: Defender of the Realm, 1940 – 1965 deals in great detail with Churchills actions during and after the war; the style is a bit different than I recall the first two being, but it's rich in information mostly culled from primary sources. It took a long time to read, because it's a very long book.
The set as a whole is worth reading for anyone with an interest in the British Empire, World War II, or even British politics. Excellent books them all...