Interesting stuff. Ancient Germany was one place even the Romans never conquered, even though they did try. The Black Forest was someplace you simply never came out of, which is why the Romans usually didn’t go there; kind of for the same reason the Romans did not regularly venture North of Hadrian’s Wall in Britain...
A couple of years ago someone unearthed the remains of a large Roman attempted retreat out of Germany where the entire Roman column had eventually been slaughtered over a miles long march. Smithsonian magazine had an excellent article, and I may try and did it out of the bookcase later to refresh my memory.....
That was the battle of Tutenburg Forest about 4 AD. That revolt kept the Romans out of Germany.
http://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest
Queen Boedicia’s failed revolt in England against Rome in 60 AD resulted in the annexation of England
http://en.wikipedia.org/wiki/Boudica
The Jewish revolt revolt against rome in 70 AD also failed with pretty disastrous consequences.
http://en.wikipedia.org/wiki/First_Jewish%E2%80%93Roman_War
(Jesus prophesied/alluded to this event in the New Testament.)
Perhaps you're refering to "Battle of the Teutoburg Forest."
http://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest
Germanic warriors storm the field
Teutoburg Forest
Germanic tribes led by Arminius
I think you are referring to the battle of Toutoburg Forest where the Roman Varus (thought to be the 4th most important man in Rome) was totally defeated and he along with most of his legions killed. It was during the reign of Augustus, who reportedly beat his head against a wall screaming, “Varus give me back my legions.” All this from a very detailed Wiki article which I recommend reading.