Arminius History from The Arminius Foundation

Arminius was a Germanic prince who led an army of his countrymen in a revolt that destroyed the three legions of Publius Quinctilius Varus in the Teutoberg Forest in 9 AD, thus stanching for all time the advance of the Roman Empire into Free Germany. The understanding of Roman battle tactics which Arminius had earlier obtained as commander of an auxiliary cavalry unit attached to the Roman legions fighting in Illyricum (modern Croatia) proved decisive in his victory.