Answer
In 305, Constantius Chlorus ascended to the throne as a Roman emperor. He ruled as co-emperor alongside Galerius, sharing the vast empire. Constantius's reign was marked by his successful campaigns against the Picts in Britain, securing the northern frontier of the empire. He also played a crucial role in the Tetrarchy, a system of governance that divided the empire into four regions, each ruled by a co-emperor.