"The History of Herodotus works up the materials thus collected into an artistic picture of the world, grouped round a central idea. This idea is the great struggle between East and West, between Asiatic and Greek, of which the Persian Wars formed the last chapter. The History falls into two chief parts. The first five books are an introduction, tracing the rise and growth of the Persian power. The last four books relate the Persian invasions of Greece under Darius and Xerxes."