Battle of the Teutoburg Forest

01Germanic chieftain Arminius was a Roman-trained auxiliary officer who betrayed Publius Quintilius Varus by leading the legions into a prepared ambush.
02Three legions — XVII, XVIII, XIX — were destroyed so completely that Rome retired their numbers permanently; no Roman legion ever bore those numerals again.
03Suetonius records that Augustus would bang his head against a doorpost and cry 'Varus, give me back my legions' for months after receiving the news.

Ferrofluid on glass, with a neodymium magnet underneath

In 9 AD, three Roman legions — 20,000 men — were ambushed and annihilated over three days in the Teutoburg Forest. Augustus reportedly beat his head against a wall for months, shouting: 'Varus, give me back my legions.'