Writing was invented to serve the needs of people who lived close to one another in cities and states, and almost everyone who could write lived in states. Because most history, including this book, concentrates on areas with states, the next two chapters examine the states that were developing in India and China during the period discussed in this chapter. In Chapter 5 we pick up on developments in the Mediterranean that link to those in Mesopotamia, Egypt, and Persia discussed in this chapter.

It is important to remember that, as was the spread of agriculture, the growth of the state was a slow process. States became the most powerful and most densely populated forms of human society, and today almost everyone on the planet is at least hypothetically a citizen of a state. In 500 B.C.E. perhaps only a little over 5 percent of the world’s population lived in states. In his Histories, Herodotus pays primary attention to the Persians and the Greeks, both of whom had writing and states, but he also discusses many peoples who had neither. In their attempts to provide a balanced account of all the world’s peoples, historians today are also looking beyond written sources.