This PhD thesis is in its fourth year, and is currently being written up. The system of provincial government created under Diocletian and Constantine was significantly different to that of the early empire. Governors lost their military commands, and so had less need to travel. They administered justice from a designated seat, rather than during a peripatetic tour.
Provincial assemblies seem to have followed a similar pattern, meeting in the city of the governor.
All these changes can be said to have begun a system of provincial capitals, far more pronounced than any comparable arrangement of the early imperial period. The Codex Theodosianus sets such cities apart, as do other late antique documents, such as the Nottia Galliarum and the Synecdemus of Hierocles. The term metropolis came to be associated specifically with cities containing the civil administration or the ecclesiastical primacy of a province. An empire-wide question is addressed, though the main body of the evidence comes from the eastern and central Mediterranean. The political life of provincial capitals is well documented for only a few major cities.