By warfare and reconstruction Constantius and his son Constantine had laid the foundation for 500 years of prosperity in Britain. This had been made possible only by far-reaching reforms which Diocletian and Constantine had applied to the whole empire, thereby saving it from complete dissolution and disaster. Both the civil service and the army were radically reformed, with a clear separation between the civilian and military powers, Diocletian divided the empire into twelve districts called dioceses, each governed by a Vicarius, who was technically, a deputy of one of the praetorian prefects. Britain formed one of these new dioceses, and its Vacarius was based in London. The areas of the provinces are uncertain, Maxima was in the south, with its center London, temporarily renamed Caesarea and later as Augusta, Prima was in the west, including Wales, with its capital, at that time, Cirencester! Secunda was in the north, possibly York was its capital, and in the east Flavia's capital may have been Lincoln. In 369AD, a fifth province called Valentia (named in honor of the reigning emperors, Valentinian & Valens) was established under a consular governor, and probably located in northern England with its capital at Carlisle.