An historian is only as good as his sources, and an assessment of any historian rests primarily on an assessment of his ability to find, to choose, and to utilise historical sources. In this regard we may, I believe, credit Ephorus, the most important of the fourth century B.C. historians, with a large degree of achievement. Before we turn to the main body of this paper, however, I must prefix some comments on the size and nature of the Ephoran corpus which chance has transmitted to us. Felix Jacoby consciously chose not to print all that has survived of Ephorus under FGrHist 70. Jacoby limited himself to those passages which specifically cited Ephorus as author of the transmitted information.