The present dissertation is based on a new examination of the textual tradition of Isocrates' Helen and Plataicus, consisting of 4 papyri and 45 medieval and renaissance MSS. Thorough descriptions and collations of the MSS. are provided and a stemma codicum is drawn. Also the oldest two printed editions by Demetrius Chalcondylas (Milan 1493) and Aldus Manutius (Venice 1513) are taken into consideration. A critical edition of both speeches and respective argumenta is given. The last chapter offers philological notes to the text of the Plataicus
