Herodotus wrote The Histories, a long inquiry into why Greeks and Persians fought and who lived in the world they knew. He came from Halicarnassus, now Bodrum in Turkey. This is Book 5, called Terpsichore. In Book 4, the Persian king Darius marched north into Scythia, the grassland above the Black Sea, found no cities to take, and came home through Thrace with little to show.

Aristagoras, lord of Miletus, a Greek city on the coast of western Turkey, botches a war on Naxos and starts the Ionian Revolt rather than fall. Histiaeus, his father-in-law, held as a hostage at Darius’s table, sends a slave with a shaved head and a message in the stubble. Athens and Eretria send ships — the beginning of evils, Herodotus says, for both sides. Sardis, the old Lydian capital now in Persian hands, burns. Cleomenes, king of Sparta, looks at a map of Asia and sends Aristagoras away. Athens is easier: twenty ships. Hippias, Athens’s exiled tyrant, waits at the Persian court. Megabazus chains the towns of the Hellespont, the Dardanelles. Marathon is not yet; the insult that leads there is.