AC:Odyssey got me wanting to get back into studying ancient Greece (who says games are good for nothin)
reading A War Like No Other: How the Athenians and Spartans Fought the Peloponnesian War
Brutal. I've known cursory information about the Peloponnesian war, but this goes in-depth on just how truly insane this war was, and the people, politics, geography, religion, even agriculture's role. Wracked by plague that kills nearly a quarter of the population, Athens is nearly brought to it's knees right at the outset. Even claiming Pericles himself, and his family.
The methodology and tactics of the war evolved is pretty fascinating: the evolution of the hoplite phalanx, fighting "honorable" battles, to the descent into lightly armored mercenaries, guerilla tactics, and wholesale slaughter of combatants and non-combatants alike.
I'm about halfway, and while it's an exhaustive account of the history, I'm still pretty gripped. It definitely helps to know a bit about the region, factions, and personalities of the era, as there's a lot of names being dropped. I've had to stop and google more than once!