Today marks the two thousand year anniversary of the first day of the Battle of the Teutoburg Forest. On September 9 in the year 9 C.E., under the leadership of Arminius (Hermann or Irmin the Cheruscan) warriors from several Germanic tribes sprang an ambush on a column of three legions of Roman soldiers (approxinately 18,000 men). When the battle ended on September 11, the Romans had been annihilated (approximately 16,500 dead in battle, almost all the survivors subsequently sacrificed to the gods) and only about 500 Germanic warriors lay dead. The former governor of Gaul and designated governor of Germania, Varus, fell on his sword. The news drove the Emperor Augustus half mad. For the first time, Rome turned back from a projected conquest. They withdrew to the Rhine (Julius Cæsar's earlier border), and erected a wall, the limes, to keep the Germanic tribes from attacking their territories. They contented themselves with the Alpine and Danubian territories and with the Rhineland and left the rest of the continental Germanic peoples alone.
This was a great victory by ancient heathens who came together against a common foe of immense power.
On the voluspa.org lore site (which I recommend anyway), there is a special Teutoburg portal. If your connection can stand a slideshow, the main page is here; the first of seven essays on the background to the battle, the battle itself, and how it has reverberated through history can be found here.