Sometime around 450 BC in ancient Greece, a young Thucydides went with his father to hear the historian Herodotus speak. After the lecture, Thucydides announced that writing history was his life’s calling. He later wrote History of the Peloponnesian War, a chronicle of the 27-year civil war between the Athenians and the Spartans. Thucydides believed that history is cyclical, and he saw written history as more than just record keeping. He wanted to know why certain events unfolded as they did. In fact, Thucydides is one of the first Western historians to document a historical event year by year.   Professor Richard Billows is a professor of History at Columbia University. He specializes in Ancient Greek and Roman history. He is the author of Before and After Alexander and Marathon: The Battle that Changed Western Civilization, among other books. See more information on our website, WritLarge.fm. Follow us on Twitter @WritLargePod.