To understand Gibbon’s History of the Decline and Fall of the Roman Empire properly it is necessary to have knowledge of his historiographical and philosophical context. Gibbon is considered here not just for what he reveals of eighteenth-century intellectual attitudes, but for his forceful interpretation of the period. Leading experts in the field about which Gibbon himself wrote enter into dialogue with historians of the eighteenth century. New light is thereby thrown not only on Gibbon’s text, but also on the degree to which he can be regarded as a trustworthy guide to late antiquity and the Middle Ages in the late twentieth century.