Into the Teutoburg Forest

In 9 AD, the Roman governor Publius Quinctilius Varus led three legions — roughly 20,000 soldiers — through the dense Teutoburg Forest in Germania. He trusted his guide completely.

That guide was Arminius, a Germanic chieftain raised in Rome and trained as a Roman officer. He had secretly switched sides. Over three days, the Germanic tribes wiped out the entire force. Rome never again managed to permanently conquer Germania.