A German population already in Rhætia, the Agri Decumates, and in Elsass.
In order fully to comprehend the meaning and consequences of this German colonisation of Roman provinces, it must be borne in mind that the rich lands on the left bank of the Rhine, between the Vosges mountains and the river, had been settled [p282] by Germans before the time of Tacitus. Strabo[404] distinctly says that the Suevic tribes, who in his day dwelt on the east bank of the Rhine, had driven out the former German inhabitants, and that the latter had taken refuge on the west bank. Tacitus describes three German tribes as settled in this district (now Elsass).[405] Further, the large extent of country to the east of the Rhine, within the Roman lines, reaching from Mayence to Regensburg, included in the Agri Decumates and the old province of Rhætia (i.e. what is now Baden, Wirtemberg, and Bavaria), had by the third century become filled with straggling offshoots from various German and mostly Suevic tribes who had crossed the 'Limes'—a mixed population of Hermunduri, Thuringi, Marcomanni, and Juthungi, with a sprinkling of Franks, Vandals, Longobards, and Burgundians,—some of them friendly, some of them hostile to the empire and gradually becoming absorbed in the greater group of the 'Alamanni.'
The Alamanni.
The Limes, or 'Pfahlgraben.'
Further, it should be remembered that in the third century offshoots from the Alamanni and the Franks attempted to spread themselves over the country on the Gallic side of the Rhine, assuming, during periods of Roman weakness, a certain independence and even over-lordship, so that Probus found sixty cities under their control. Probus completely reduced them once more into obedience, and again made the Roman authority supreme over the 'Agri Decumates,' and Rhætia as far as the 'Limes.' [406] [p283]
A few years before, Marcus Antoninus, after he had conquered the Marcomanni in this district, had deported many of them into Britain.[407]
Forced colonisation in Britain and Belgic Gaul.
Probus followed his example, and deported also into Britain such of the Burgundians and Vandals from the 'Agri Decumates' as he could secure alive as prisoners, 'in order that they might be useful as security against revolts in Britain.' [408]
Of Læti in Belgic Gaul and the Moselle Valley.
He also colonised large numbers of Germans in the Rhine valley (where he introduced, it is said, the vine culture), and some of them in Belgic Gaul. In his report to the Senate he described his victory as the reconquest of all Germany. He boasted of the subjection of the numerous petty kings, and declared that the Germans now ploughed, and sowed, and fought for the Romans. And, as he himself had deported Germans into Britain, his words cover the British as well as the Gallic and German provinces.[409] This victory over the Alamannic tribes and colonisation of them in Britain and Gaul, by Probus, was in A.D. 277.