TLDR. Eliminating three legions was a fluke
[QUOTE=PedroMorales;2644130]You do know the Germans kicked the shit out of the Romans, eliminating entire legions, right?.[/QUOTE]First, half of the Roman Imperial Army was of Germanic origin (mercenary, auxiliary forces called Foederati). Arminius was a Roman citizen of Germanic origin, who acted as a "trusted" advisor to Varus, the commander of the three Roman legions. Arminius fabricated a story about a revolt that needed to be urgently put down, and advised Varus to move his force through a narrow, unknown route via a swampy forest. Unbeknownst to Varus, Arminius had been conspiring with chieftains from various Germanic tribes, and had orchestrated the ambush.
Second, a few years later, several legions led by Germanicus returned to Germania to retaliate. The Germanic tribes responsible for the treachery were hunted down like dogs. These later campaigns proved that the Romans, had they chosen to do so, could have easily pushed the Germanic tribes beyond the Elbe River.
Third, the Romans realised that they had already expanded their empire to their natural limits. The cost of conquering and administering Germania would be more than what they could possibly take in from tax revenues (cold, forested, inhospitable). As such, the Romans decided to stop their expansion at the Rhine.
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From the time of the rediscovery of Roman sources in the 15th century, the Battles of the Teutoburg Forest have been seen as a pivotal event resulting in the end of Roman expansion into northern Europe. This theory became prevalent in the 19th century, and formed an integral part of the mythology of German nationalism.
More recently some scholars questioned this interpretation, advancing a number of reasons why the Rhine was a practical boundary for the Roman Empire, and more suitable than any other river in Germania. Logistically, armies on the Rhine could be supplied from the Mediterranean via the Rhone, Saone and Mosel, with a brief stretch of portage. Armies on the Elbe, on the other hand, would have to have been supplied either by extensive overland routes or ships travelling the hazardous Atlantic seas. Economically, the Rhine was already supporting towns and sizeable villages at the time of the Gallic conquest. [b]Northern Germania was far less developed, possessed fewer villages, and had little food surplus and thus a far lesser capacity for tribute.[/b] Thus the Rhine was both significantly more accessible from Rome and better suited to supply sizeable garrisons than the regions beyond. There were also practical reasons to fall back from the limits of Augustus' expansionism in this region. [b]The Romans were mostly interested in conquering areas that had a high degree of self-sufficiency which could provide a tax base for them to extract from. Most of Germania Magna did not have the higher level of urbanism at this time as in comparison with some Celtic Gallic settlements, which were in many ways already integrated into the Roman trade network in the case of southern Gaul. In a cost/benefit analysis, the prestige to be gained by conquering more territory was outweighed by the lack of financial benefits accorded to conquest.[/b]
https://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest
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