392 THE DECLINE AND FALL CHAP, their territory. He even entertained some thoughts • of compelHng the Germans to reUnquish the exercise of arms, and to trust their differences to the justice, their safety to the power, of Rome. To accomphsh these salutary ends, the constant residence of an im- perial governor, supported by a numerous army, was indispensably requisite. Probus therefore judged it more expedient to defer the execution of so great a design ; which was indeed rather of specious than solid utility '^. Had Germany been reduced into the state of a province, the Romans, with immense labour and ex- pense, would have acquired only a more extensive boundary to defend against the fiercer and more active barbarians of Scythia. He builds a Instead of reducing the warlike natives of Germany the Rhine ^^ ^^^ condition of subjects, Probus contented himself to the with the humble expedient of raising a bulwark against their inroads. The country which now forms the circle of Swabia, had been left desert in the age of Augustus by the emigration of its ancient inhabitants'. The fertility of the soil soon attracted a new colony from the adjacent provinces of Gaul. Crowds of ad- venturers, of a roving temper and of desperate fortunes, occupied the doubtful possession, and acknowledged, by the payment of tithes, the majesty of the empire*. To protect these new subjects, a line of frontier garri- sons was gradually extended from the Rhine to the Danube. About the reigii of Hadrian, when that mode of defence began to be practised, these garrisons were connected and covered by a strong intrenchment of trees and palisades. In the place of so rude a bul- wark the emperor Probus constructed a stone wall of a considerable height, and strengthened it by towers at If Hist. August, p. 238, 239. Vopiscus quotes a letter from the emperor to the senate, in which he mentions his design of reducing Germany into a province. 8 Strabo, 1. vii. According to Velleius Patercuius, (ii. 108.) Marobo- duus led his Marcomanni into Bohemia : Cluverius (German. Antiq. iii. 8.) proves that it was from Swabia. ' ' These settlers from the payment of tithes were denominated, Decumates, Tacit. Germania, c. 29.
