This project was begun during a most pleasant year as Whitehead Professor at the American School of Classical Studies in Athens in 1995–1996. Revisiting many of the Persian and Persian War sites under the guidance of John Camp and William Coulson gave considerable inspiration. The staff of the American School did everything to make the year productive and enjoyable. I am grateful for the helpful suggestions of John Dillery, Kevin Clinton, and Robert Garland, who read the manuscript at various stages. As always I owe most to my wife Mary, for expert editorial assistance and especially for her constant support and patience.