* The generous hospitality of the Maison Suger and of the Bibliothèque of the Ecole Normale Supérieure made it possible in July 2000 for me to do the work on the study that has given rise to this paper. The opportunity of delivering it at the Triennial Meeting of the Greek and Roman Societies in July 2001, along with Rhiannon Ash, to whose paper on Corbulo it was a pendant, and contributions from our audience, have improved it greatly.