The Empress for Pax Romander

David Frum: How much credit can you give the Empress for Pax Romander and how much was it just kind of good timing and circumstance? He says that there are very few emperors who qualitatively affect the running of the empire. Hadrian is one of them, as well as Diocletian or Constantine. The idea of Rome as a world empire endures right up to the 15th century according to Frum.