For long generations Germania had been seething with disorder, for reasons which cannot here be considered. Tribe was pressing on tribe; the whole mass of wild barbarism was being forced against the Rhine and the Danube, behind which lay the Roman Empire, sorely weakened by invasions, plague, famine, economic decay, and misgovernment. The North-German tribes--Franks, Saxons, Angles, Jutes, Frisians--finding raids over the Rhine difficult, dangerous, and more and more unremunerative, began to take to the sea. Their craft as yet--perhaps to the end--were small open vessels, incapable of rough sea-work, and obliged to hug the shore as far as possible. The raiding flotillas ran down what are now the coasts of Denmark, North-West Germany, and Holland, and turned to right or left on Britain or Gaul, according to information or inclination. Others, more daring, or encouraged by spells of fine weather, ran across from Frisia to the coasts of Essex, Suffolk, and Norfolk, and landed for hasty raids on those rich agricultural districts. These appear at first to have been met merely by detachments of troops; the Roman naval force in the Channel was small. But when the famous organizer and statesman, Diocletian, took up the task of saving the Empire in 284, he abandoned timid defensive strategy. His colleague, Maximianus, to whom he entrusted the West, organized a great fleet in the Channel, and placed in command a distinguished naval officer, Marcus Aurelius Carausius, with the title of ‘Count of the Saxon Shore.’ He cleared the sea of the pirates, but, presently accused of misappropriation of booty, set up in Britain as independent ruler. He even endeavoured to conquer Gaul, but only succeeded in permanently holding Gessoriacum (Boulogne). His naval power, however, rendered his position invulnerable, and Diocletian and Maximianus stooped to acknowledge him as their colleague. He was assassinated in 293, but his murderer and successor, Allectus, held the province for three years longer. He was not the equal of Carausius, and allowed Constantius Chlorus, Cæsar of the West, to build ships unmolested in Gaul until he was able to cross the Channel and overthrow Allectus (296).