The Roman Emperor in Britain at this time was Constantius who had been sent over in 293AD. He was campaigning in northern
Britain and had popped back to York for the winter and, sadly, also popped his clogs which, for those of you who don’t know, means he died. Constantius’ soldiers
decided his son, Constantine, yes imagination was short in the Roman era, should be the new emperor.
This resulted in a few wars between various Roman emperors but in the end Constantine won and actually abolished the four emperors idea and became the
sole ruler of the Roman Empire, both west and east by 324AD. He did however leave Britannia in four parts.