This edition is the first to be based on full knowledge and analysis of the manuscript tradition down to the fourteenth century. Detailed collations of forty manuscripts have been used, fourteen more than were available to the last editor, D. L. Page. Although the tradition is pervasively contaminated, it has proved possible to sort the manuscripts into families, and to form a clearer picture of the activities of the Byzantine scholars. The contributions of textual criticism since the time of the early humanists have been carefully sifted. Many emendations have been found to be wrongly assigned; in particular, Auratus' reputation turns out to have been inflated by wholesale misattribution, at the expense of the lesser-known Franciscus Portus. The ending of one of Aeschylus' famous odes in praise of Zeus is perfected by an incontrovertible nineteenth-century correction now rescued from a century of total oblivion; and very many other passages benefit from the editor's thorough and careful reconsideration. A feature of the critical apparatus is that, wherever possible, it indicates the place of publication of each conjecture mentioned. The long Praefatio contains, besides an account of the manuscripts and other sources for the text, a compendium of Aeschylean morphology and prosody, with detailed discussion of orthographical questions. The text and apparatus are accompanied by a citations register and followed by metrical analyses of the lyric portions.