This book offers an interpretation of the first 500 years of history writing as a moral-didactic genre, and argues that this does not invalidate ancient Greek historiography as history. In Part I, it offers a thorough analysis of the moralising techniques and moral-didactic lessons of Polybius and Diodorus Siculus and then analyses the fragments of a range of less well-preserved Hellenistic works of historiography (Timaeus, Phylarchus, Duris, Hieronymus, Agatharchides, and Posidonius) to see how far it is possible to trace similar techniques and lessons in these works. In Part II, the roots of Hellenistic historiographical moralising are traced in the Classical works of Herodotus, Thucydides, and Xenophon, and the fragments of the Oxyrhynchus Historian, Ephorus, and Theopompus. The book concludes that the Greek genre of historiography was moral-didactic from its inception, like most of the Classical Greek literary genres, and that this purpose became explicit and its techniques formalised in Hellenistic times, but that neither the writers nor the readers of the genre believed this moral-didactic purpose to be detrimental to the truth-value of historiography. Ancient historiography was history writing with an agenda: it was Moral History (in the same way that some modern historiography can be defined as, say, Feminist History or Postcolonial History), but it was still History.