was to form an effective barrier between themselves and the restless barbarian tribes of the Teutonic North, the constant menace of whose invasion lay as a canker at the heart of rich and fruitful Italy.  With the terror of a barbarian inroad ever before their eyes, the cohorts of the Imperial City constructed a formidable vallum, or earthen wall, from the vicinity of Linz to Regensburg, on the Danube, a distance of three hundred and fifty miles, for the purpose of raising a barrier against the advance of the warlike men of the North.  They further planted a colony of veterans in the Black Forest neighbourhood in order that invasion might be resisted from that side.  But as the Empire began to exhibit signs of decadence the barbarians were quick to recognize the symptoms of weakness in those who barred their advance to the wealthy South, the objective of their dreams, hurled themselves against the boundary, now rendered feeble by reason of the withdrawal of its most experienced defenders, and, despite a stern resistance, flooded the rich valleys of the Rhine, swamped the colonies on the left bank which had imbibed Roman civilization, and made all wholly Teutonic.

The Rebellion of the Barbarians

This was, however, a process of years, and by no means a speedy conquest.  The closing years of Augustus’ reign were clouded by a general rising of the Rhine peoples.  Quintilius Varus, an officer who had been entrusted with the government of the provinces beyond the Rhine, proved totally unequal to curbing the bolder spirits among the Germans, who under their chief, Arminius, boldly challenged the forces of this short-sighted officer.  Arminius belonged to the Cherusci.  He had served with the German horsemen in the Rhenish armies, and was conversant with the Latin language.  Observing that half, at least, of the Roman forces were on leave, he incited the tribes of Lower Saxony to revolt.  The weak Varus, who had underestimated the influence of Arminius, attempted to quell the rising, but without success, and the bank of the river was the scene of a wholesale slaughter.  Varus, completely losing his nerve, attempted to separate the cavalry from the infantry and endeavoured to escape with three squadrons of the former; but the Germans surrounded them, and after a hand-to-hand struggle of three days the Roman army was annihilated.  The news of this disaster prompted the aged Emperor to dispatch his son Tiberius to suppress what appeared to be a general rising of the North.  The Rhenish tribes, however, were too wary to meet the powerful force now sent against them in the open field, and during the remainder of the year Tiberius, left in peace, occupied himself in strengthening the Rhine fortifications.