The Evolution of the Roman Empire

Antoninus kept on most of Hadrian's staff and extended bureaucracy. The real shift was the extension of pro-consulships to terms of five years or more. Antoninus saw constant office rotations as a bug rather than a feature of imperial administration. A pro-curator would spend a year in some province before being replaced by someone else who knew nothing about anything. It was silly, and on the frontier provinces, it was dangerous.