Orestes, produced in 408 BC towards the end of Euripides' life, was one of the most popular Greek tragedies in antiquity, and was consequently preserved in a large number of medieval manuscripts. Having investigated about sixty of the most important, James Diggle explains the complicated relationships which exist among them. He also examines afresh the contribution of the papyri and quotations which preserve parts of the play. In the course of these analyses he throws much light on problems of text and interpretation, on metre, and on the activities of Byzantine scholars.This examination of Orestes is the last major task in the completion of the study of the Euripidean manuscript tradition. As such it will be indispensable to all students of the transmission of Greek tragedy.