This prologue is one of Euripides’ best. They are often interminable and marred by long genealogies and other jejune matter. Some of them are not undeserving of the strictures which critics, both ancient and modern, have heaped upon them. Yet they served many useful purposes, too, and there is no warrant for utterly condemning the type as a whole. We have already seen (p. 258, above) that such a device enabled a dramatist to circumvent the conditions which caused the conventional observance of the unities of time and place and to bring earlier events more explicitly within the scope of his play. The fact that Euripides more often chose different themes for the plays in each group instead of writing trilogies or tetralogies made brevity of exposition a desideratum. Again, a desire for novelty and the fact that Aeschylus and Sophocles had anticipated him in so many of his subjects caused him to depart widely from the traditional accounts. Unless some warning of this were given, it would sometimes be almost impossible for the ordinary spectator to comprehend the action, and no other place was so appropriate for such an explanation as the prologue. For example, in the _Helen_, Euripides abandoned the account given by Homer and most others in favor of the version invented by Stesichorus. The audience had to comprehend not only that Helen had been the chaste and loyal wife of Menelaus throughout but also that there were two Helens—one the true Helen who spent the years of the Trojan War in Egypt, and the other a cloud-image Helen who eloped with Paris and was recovered by Menelaus at the capture of the city. Surely a very clear statement was required to render such a revamping of the legend clear to everyone. Even the genealogical table was not without its utility in this prologue, for the Egyptian king Theoclymenus and his sister would mean nothing to most spectators until their lineage was traced to the familiar names of Proteus and Nereus.