the legendary VarusschlachtTheir calling the battle legendary was hilarious -- it didn't survive as a legend; it was rediscovered in modern times from classical sources and used to fuel nationalism. The 19th century project to build the monument (many miles from the actual site of the battle, as it later turned out) slightly preceded the Kulturkampf. Arminius himself was located and attacked by a later Roman army, and after it started to turn in favor of the Romans, he wussed out and ran for it; not many years after that second battle he was caught and killed by his fellow (ancient) Germans.
Well, if you consider ~1500 to be modern times (that’s when Tacitus was rediscovered, and when the legend around that battle and Arminius began to be built).