Who was Arminius?

Arminius (German: Hermann; 18/17 BC – AD 21) was a chieftain of the Germanic Cherusci who defeated a Roman army in the Battle of the Teutoburg Forest in 9 AD after betraying Varus, the Roman general, of whom he was an auxiliary officer. Arminius's influence held an allied coalition of Germanic tribes together in opposition to the Romans, but after defeats by the Roman general Germanicus, nephew of the Emperor Tiberius, his influence waned, and Arminius was assassinated on the orders of rival Germanic chiefs.

Arminius's victory against the Roman legions in the Teutoburg forest had a far-reaching effect on the subsequent history of both the ancient Germanic peoples and on the Roman Empire. The Romans were to make no more concerted attempts to conquer and permanently hold Germania beyond the river Rhine. Modern historians have regarded Arminius's victory as "Rome's greatest defeat" and one of the most decisive battles in history.