You can slice history a lot of different ways, and this authors has decided to slice it horizontally into rank and extract the four five-star admirals of World War II. I knew Nimitz pretty well already, but knew not a lot about King and Halsey and virtually nothing about Leahy, so I thought I'd take this opportunity to learn something new.
It was a good book, although the highly artificial subject matter meant that the author was constantly jumpring back and forth just to keep the focus on the four individuals, and not on what they were doing. It wasn't as distracting as you might think, since all had similar backgrounds dating back to the Naval Academy, so the story was of interest throughout.
I learned the most about Leahy, who I vaguely remembered was chief of staff to FDR, but I didn't really understand the extent to which Leahy ran the presidency for FDR as the latter's failing health increasingly hampered his ability to run the country and the war. You also see almost out of the corner of your eye the indispensable role that the Army Chief of Staff George Marshall played, and once again I get to see the story of how the United States went from being what, the seventh army in the world in size on the eve of war to the behemoth it become by 1945. This book tells the story of the role the four "fleet" admirals played in that during the war.
King deserves a lot of the credit for doing his job as CNO and CominCh very well, despite significant personal shortcomings, and Nimitz and Leahy get credit for being efficient and talented in dealing with people in general in the former's case and FDR in the latter's. Halsey is just out of his depth as the war went on, going from a courageous task force commander to a enormously influential regional commander to a woefully inadequate fleet commander by 1944-45. But sa the others all knew, the Navy needed its heroes too, and just as the failings of the Army's Douglas MacArthur were covered up, so too were Halsey's - to the extent that he ended up with the five star rank that by rights should have belonged to Admiral Raymond Spruance, who helped win Midway with Rear Admiral Frank Jack Fletcher in 1942, and who administered the Fifth Fleet with notable efficiency and success during his tours as commander in 1944 and 1945.
All in all, a useful book - but I can't say I know a single person I'd recommend it to.