This book contains the proceedings of a colloquium held at Lyons in 2005. The title of section 1 is a question: ‘Christianisation du pouvoir?’ François Richard observes that the Church extended a ‘pouvoir spirituelle’ to the government, at once perpetuating and superseding the protection that had been afforded by the old Roman gods. Elio Dovere finds that legislation proscribing heretics embodies not the emperor's personal judgement, but the views of the dominant party at the last council, while Emmanuel Soler's review of the laws against Donatists and the Arians reveals that the tone is softer when the enemy is well-armed. In the view of Gian Luigi Falchi the laws of Constantine maintain a separation of imperial and ecclesiastical powers, though not the innovative and principled tolerance that Laurent Guichard discovers in the taut style of Valentinian i. Christel Freu reveals that the laws which required rich ordinands to give up their patrimony were designed to forestall abuses that were also deplored by clerics. Beatrice Caseau, reviewing the use of the term profanus in the Theodosian code, concludes that it is generally pejorative, and better translated ‘impious’ than ‘profane’. Josep Villela argues that the first and fifty-ninth canons attached to the questionable Council of Elvira presuppose a general interdict on sacrifice, and therefore cannot antedate the reign of Constantine. This section ends with Richard Puza's lucid survey of recent works on the relation between imperial and ecclesiastical law. The limits of secular patronage are examined in section 2, ‘un aide reciproque’, where Roland Delmaire contends that the dispensations which the Church received under Constantine were retrenched by successive emperors, while Olivier Huck suspects that bishops may not have welcomed the crown's incorporation of episcopal audience into its machinery of justice. On the other hand, Carlas Perez finds that the estates of the Church were enriched by the accession of properties confiscated from heretics and Jews, while Karl Noetlichs ascertains that murals and baptismal fonts were among the treasures subsidised by the exchequer. Rites and burdens furnish subjects for nine essays in section 3, ‘Defense de l'orthodoxie et de la morale’. Angelo di Berardino notes the separation of games from festivals as a feature of calendrical legislation, while Klaus Girardet traces the origins of the Christian Sunday to a law addressed by Constantine to his soldiers in 311/12. Victoria Pano, Antonella Todini and Andrea Cococcia show how legal disabilities could add weight to the objurgations of the church. The sack of Rome by Alaric, according to Capucine Nemo-Pekelman, obliged the state to discriminate more rigidly between true Christianity and its Jewish counterfeit; at the same time, as Patrick Laurence shows, Roman custom tempered the severity with which Christian principles of female conduct could be enforced. Claude Lepelley points out that it was the unanimous election of Augustine as bishop of Hippo that secured his exemption from municipal duties; in a fittingly ambivalent peroration to the volume, Claude Degans discusses the unease with which such men enjoyed the benefits of coercion and largesse.