The ‘Constantinian revolution’ not only forced Christianity to re-assess itself in relation to its own past. It also raised other, far-reaching, questions about the nature of the community and the communities that it considered itself to be, and their interrelationships. Christians experienced their Church both as a single community spanning heaven and earth, past and present, and as a multiplicity of communities, each in its way mirroring the one Community which, collectively, they constituted. The universal intersected with the particular in their own, local, groups. How were these individual ‘churches’ to see themselves in relation to the ‘great Church’, past and present? How were they to conceive of themselves in relation to the social world around them? How was the sense of their personal Christian calling reflected in the group identity of their church, or of other groups generated to give it expression?