mentioned subject to the Romans--is uncertain and at least inadequate, there is here greater probability than in the case of the Alamanni that the Germans hitherto dependent on Rome on the right bank of the Rhine, and the Germanic tribes previously dislodged from the Rhine, took at that time--under the collective name of the "Free"--the offensive in concert against the Romans. [Sidenote: Gallienus.] [Sidenote: Postumus.] So long as Gallienus himself remained on the Rhine, he, notwithstanding the small forces that were at his disposal, kept his opponents to some extent in check, prevented them from crossing the river, or drove out again the intruders, although he doubtless ceded to one of the Germanic leaders a portion of the desired territory on the river-bank, under the condition of his acknowledging the Roman rule and defending his possession against his countrymen--which indeed almost amounted to a capitulation. But when the emperor, recalled by the still more dangerous position of affairs on the Danube, resorted thither and left behind as representative in Gaul his elder son still in boyhood, one of the officers, to whom he had intrusted the defence of the frontier and the guardianship of his son, Marcus Cassianius Latinius Postumus,[94] got himself proclaimed by his men as emperor and besieged in Cologne Silvanus the guardian of the emperor's son. He was successful in capturing the town and in getting into his power his former colleague as well as the imperial boy, whereupon he had them both executed. But during this confusion the Franks burst over the Rhine, and not merely overflowed all Gaul, but penetrated also into Spain and indeed pillaged even the coast of Africa. Soon afterwards, when the capture of Valerian by the Persians had filled up the measure of misfortune, all the Roman land on the left bank of the Rhine in the upper province was lost, passing doubtless to the Alamanni, whose eruption into Italy in the last years of Gallienus necessarily presupposes this loss. He is the last emperor whose name is found on monuments on the right of the Rhine. His coins celebrate him on account of five great victories over the Germans, and not less are those of his successor in the Gallic rule, Postumus, full of the praise of the German victories of the deliverer of Gaul. Gallienus in his earlier years had taken up the struggle on the Rhine not without energy, and Postumus was even an excellent officer and would gladly have been a good regent; but amidst the utter unruliness which then prevailed in the Roman state or rather in the Roman army, the talent and ability of the individual profited neither himself nor the commonwealth. A series of flourishing Roman towns was at that time laid desolate by the invading barbarians, and the right bank of the Rhine was for ever lost to the Romans. [Sidenote: Aurelianus.]