Constantius I, commonly known as Constantius Chlorus, was Roman Emperor from 293 to 306. He was the father of Constantine the Great and founder of the Constantinian dynasty. As Caesar he defeated the usurper Allectus in Britain and campaigned extensively along the Rhine frontier, defeating the Alamanni and Franks. Upon becoming Augustus in 305, Constantius launched a successful punitive campaign against the Picts beyond the Antonine Wall. However, Constantius died suddenly in Eburacum (York) the following year. His death sparked the collapse of the tetrarchic system of government inaugurated by the Emperor Diocletian.