***Publius Quinctilius Varus blundered into a German ambush that obliterated three full Roman legions plus their auxiliaries.***
“VARUS! GIVE ME BACK MY LEGIONS!”-Augustus
“Lord Augustus each time bawling
As he fetched his head a crack,
‘Varus, Varus, General Varus,
Give me my three Eagles back!’”
“Lord Augustus tore his bedclothes,
Blankets sheet and counterpane,
‘Varus, Varus, General Varus,
Give my Regiments back again!’”—from I CLAUDIUS by Robert Graves.
Beat me to it. Always glad to hear of another Roman history buff.
*Publius Quinctilius Varus blundered into a German ambush
Arminius (the Barbarian leader) was an ex-roman legionnaire and as such would have been intimately familiar with the layout of legionnaire encampments. I suspect it was a night slaughter by vastly outnumbered Germanic natives who took advantage of the overconfident, sleeping Roman invaders.