The Roman Empire was very powerful, especially in AD 117, when they controlled most of Europe. The emperor was Julius Caesar. (I think there were more, but I can't be bothered to list all of them.) They were very civilised, at the time, and apparently knew how to keep order.
1. Brian - "Bloody Romans"
2. Reg - "Apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?"