Because the barbarian invasions were not sudden but gradual, it was possible for many Roman citizens to ignore their significance. Though they bewailed the fact that the times were not as good as they once had been, they tried to go on living as if nothing had changed. But every now and again a sudden shock would wake them up to reality and force them to acknowledge the extent of what had already decayed or

been destroyed. It was only the more woeful preachers, like Salvian, who insisted on reminding everyone in season and out of season that the barbarians were no longer at the gates but within them. Most people tried to imagine that things were not so bad as they seemed. Nevertheless it was necessary for everyone to adjust himself to the new circumstances. It might be done in a moment of clear-sightedness, or in a moment of panic, or blindly and unconsciously, but it had to be done somehow; and at our distance of time it is possible to pick out three general types of reaction. One could retreat into oneself and, like St Augustine, concentrate simply on the kingdom of God; or one could collaborate with the barbarians in the belief that the better of them would appreciate Roman civilization and be content to live in amity with the Romans; or one could fight back, as did the Emperor Justinian. Many people, of course, reacted first in one way and then in another; but the three main types are most conveniently treated in isolation and in turn.