a Roman of fairly high office himself. In Germania he states that the Gauls were once more powerful than the Germani. At that time the Helvetii were on the right bank of the Rhine south of the Main, with the Boii further down the Danube. On the left bank of Tacitus' time, the Treviri (Trier) and Nervii claimed Germanic descent, the Ubii (Cologne) were proud of it, and the Vangiones, Triboci and Nemetes were of undoubted Germanic origin. Tacitus does not say that any of them were currently Germanic or spoke Germanic, only that they were careful to distinguish themselves from the cowardly Gauls. Apparently the Celtic tribes were no longer in the Agri Decumates (right bank of Rhine) because Tacitus characterizes its population as rabble and penniless adventurers. His Annales contains brief mention of the Vangiones in connection with capturing bands of plunderers from the Chatti across the Rhine to the north (Hesse) in AD 50. The Chatti must have been overconfident to send such small numbers into Alsace, which was tenanted by both Celtic and Germanic tribes loyal to Rome and was protected by bases at Mainz and Worms. The Roman commander Publius Pomponius Secundus used cavalry from the Vangiones and the Nemetes as well as regular Roman cavalry to attack the sleeping Chatti in their open camps by night. They are said to have set free some of Varus's men who had been slaves for 40 years. His Histories describes a year of crisis for the young empire in 69, when for the first time the system established by the Julio-Claudian dynasty as a solution to civil war was severely tested by the question of succession. Nero was assassinated to rid Rome of his bad management. The Romans could not agree on a successor, inadvertently involving the provinces in their internal politics, with a nearly ruinous result. After the death of Vitellius despair prevailed along the limes regarding the continued ability of the empire to rule and enforce peace. The lag in communication allowed the peoples along the Rhine to believe that the empire had in fact disintegrated. A revolt gradually spread along the Rhine, initiated by the Batavi and other tribes of the Belgae among the Germans, and the Treviri and Lingones among the Celts (see under Batavian rebellion). They convinced the Roman legions at Moguntiacum and other bases to defect to an ad hoc Gallic