The German leader Arminius is the classic example at an individual level: after several years of serving in Rome's forces as prefect of an auxiliary unit, he used the military training and experience he had gained to lead a confederacy of German tribes against Rome, culminating in the destruction of three Roman legions in the Teutoberg Forest in 9 AD, and the abandonment of Augustus' strategy of annexing Germany as far as the Elbe river. (This strategy was never revived by later emperors).