Spartans at the Gates by Noble Smith (historical fiction 2014)

This second book in Noble's The Warrior Trilogy about the lead up to the Peloponnesian Wars follows Sons of Zeus, reviewed at the link.  With amazing descriptions of Athens and Plataea, non-stop ultraviolent action, and an awesome 9-year old murdering Skythian sidekick, I liked it even more than the first.  There was a short section when it seemed tired for a minute, but the climax is great.