This volume results from a conference of Russian and British scholars of ancient history. It studies crises of various kinds in the history of civil communities in the Graeco-Roman world. Some chapters concern the main lines of Greek and Roman political development: instability in the Greek cities, the adaptation of aristocrats to the democracy of Athens, empire and crisis in fourth-century Greece; in the Roman Republic the dictatorship, the tribunate, changes in institutional arrangements which had far-reaching but unforeseen consequences; also in Rome the transition from the Middle to the Late Empire. Others focus on particular episodes where new interpretations are possible: a 'crisis of the pyramid-builders' in Egypt which Herodotus misdated by more than a millennium; two problematic episodes in the hellenistic world, concerning Caunus, and Cius and Myrlea; in the Roman world, in connection with the transition from the Republic to the Principate an examination (particularly suitable for a Russian conference) of the interpretations of Russian scholars a century ago, and, finally, the survival of Neoplatonic communities in the Late Empire.