Our analysis of Ephorus’ fragments has led to a very different portrait of the historian and his Histories from that which has been offered by Jacoby, Schwartz and many modern critics following their path. Ephorus, we have argued, was not an erudite compiler of previous histories merely interested in ethics, but a professional historian who had a strong interest in politics, and also in both the theory and the practice of research. His advanced historiographical thinking was clearly aware of that of the best fifth-century predecessors, such as Thucydides, and it in turn became a model for later historians such as Polybius. If not the first, Ephorus was among the first who provided a definition of historiography as a discipline, emphasizing, on the basis of both his predecessors’ and his own experience, the differences between historical inquiry and other disciplines.