Christianity was in origin an urban cult. Its churches and, in consequence, its first territorial organisation were to be found in the cities of the Roman Empire. It was from these urban nuclei that missionaries set out to convert the pagani of the surrounding pagi, pays or countryside. But the England to which Christianity was reintroduced late in the sixth century was a rural land. The cities of the former Empire lay in ruins; urban functions had by and large deserted them, but their sites retained a certain aura, and some were still the seats of petty princes, centres of local power. It was to two of these cities, London and York, that Pope Gregory had directed Augustine and his fellow monks. The course of Augustine's mission did not go in the ways which the pope had anticipated. He settled in Canterbury rather than London, but of the prominence of the former Roman cities in the earliest phases of Christianity in this land there can be no question. The four earliest bishoprics were located amid the ruins of Canterbury, Rochester, London and York.

But the population lived by agriculture, and it was in the countryside, not in the towns, that the parochial system in England first took root and developed.