The Germans still more than the Pannonians and the Thracians gave the Romans occasion to feel that the existing state of things could not permanently continue. The boundary of the empire since Caesar's time had been the Rhine from the lake of Constance to its mouth (iv. 258) {iv. 247.}. It was not a demarcation of peoples, for already of old in the north-east of Gaul the Celts had on various occasions mingled with Germans, the Treveri and Nervii would at least gladly have been Germans (iv. 244) {iv. 233.}, and on the middle Rhine Caesar himself had provided settlements for the remnant of the hosts of Ariovistus--Triboci (in Alsace) Nemetes (about Spires), Vangiones (about Worms). Those Germans on the left of the Rhine indeed adhered more firmly to the Roman rule than the Celtic cantons, and it was not they that opened the gates of Gaul to their countrymen on the right bank. But these, long accustomed to predatory raids over the river and by no means forgetting the half successful attempts on several occasions to settle there, came unbidden. The only Germanic tribe beyond the Rhine, which already in Caesar's time had separated from their countrymen and placed themselves under Roman protection, the Ubii, had to give way before the hatred of their exasperated kinsmen and to seek protection and new abodes on the Roman bank (716) {38.}; Agrippa, although personally present in Gaul, had not been able, amidst the pressure of the Sicilian war then impending, to help them otherwise, and had crossed the Rhine merely to effect their transference. From this settlement of theirs our Cologne subsequently grew up. Not merely were the Romans trading on the right bank of the Rhine subjected to various injuries by the Germans, so that even in 729 {25.} an advance over the Rhine was executed, and Agrippa in 734 {20.} had to expel from Gaul Germanic hordes that had come thither from the Rhine; but in 738 {16.} the further bank was affected by a more general movement, which terminated in an invasion on a great scale. The Sugambri on the Ruhr took the lead, and with them their neighbours the Usipes on the north in the valley of the Lippe, and the Tencteri on the south; they attacked the Roman traders sojourning among them and nailed them to the cross, then crossed the Rhine, pillaged the Gallic cantons far and wide, and, when the governor of Germany sent the legate Marcus Lollius with the fifth legion against them, they first cut off its cavalry and then put the legion itself to disgraceful flight, on which occasion even its eagle fell into their hands. After all this they returned unassailed to their homes. This miscarriage of the Roman army, though not of importance in itself, was not to be despised in presence of the Germanic movement and even of the troublesome feeling in Gaul; Augustus himself went to the province attacked, and this occurrence may possibly have been the immediate occasion for the adoption of that