This is the first volume of a three-volume historical and literary commentary on the eight books of Thucydides, the great fifth-century BC historian of the Peloponnesian War between Athens and Sparta. Of the three books covered in this volume, Book I presents Thucydides'' aims in writing the work and the historical background to the war. Books II and III describe the main events of the first five years of the war (431-426) and include Pericles'' funeral oration, the plague of Athens, the revolt of Mytilene, the destruction of Plataea, and civil war in Corcyra. Thucydides intended his work to be `an everlasting possession'' and the continuing importance of his work is undisputed. Simon Hornblower''s commentary, by translating every passage or phrase of Greek commented on, for the first time allows the reader with little or no Greek to appreciate the detail of Thucydides'' thought and subject-matter. It is the first complete commentary written by a single author this century and explores both the historical and literary aspects of the work. A full index is provided at the end of the volume.