The reign of Alexander the Great has always engrossed the interest of countless readers, and, not surprisingly, the interest has stimulated a flood of biographies. In 1976 it could be said that books on Alexander were appearing at the rate of more than one a year, and the last decade has not witnessed any slackening of publication. A new monograph therefore requires apology and justification. That may in part be provided by the circumstances of writing. Originally this work was conceived as a contribution to Volume vi of the Cambridge Ancient History, designed to give a survey of the period for the informed reader, with reference to the most recent literature. What emerged exceeded all reasonable bounds for a general history, and the Cambridge University Press generously undertook to publish a revised version as a book in its own right. My work is a synthesis of recent research and at the same time represents a distillation of my own thinking. It forms part of a tetralogy. My two-volume Commentary on Arrian's History of Alexander (part 11 not yet published) provides the detailed exposition of evidence and technical discussion of historical and textual cruces. The general historiographical principles of research on Alexander are expounded in my new monograph, From Arrian to Alexander: Studies in Historical Interpretation (Oxford, 1988). In the present work I draw explicitly on my more specialist studies to provide a composite narrative history of the period.