A really great one-book study of the Peloponnesian War. Roberts puts a lot of historical context around the war, resisting the simplistic narrative of "Sparta beat Athens". In truth, Sparta did temporarily gain the upper hand, but in the war had complicated consequences for its future, so it couldn't be said to be a net positive, and isn't that the history of all wars in the end? I've been reading a lot about Greek history lately and this is one of the best books I've read yet, nuanced but also very readable. Highly recommended as an introduction to the subject, or if you're just not up for a four-volume history.