"Arminius (18/17 BC – 21 AD) was a Roman officer and later chieftain of the Germanic Cherusci tribe who is best known for commanding an alliance ...
of Germanic tribes at the Battle of the Teutoburg Forest in 9 AD, in which three Roman legions under the command of general Publius Quinctilius Varus were destroyed. His victory at Teutoburg Forest would precipitate the Roman Empire's permanent strategic withdrawal from Magna Germania. Modern historians have regarded Arminius' victory as one of Rome's greatest defeats. As it prevented the Romanization of Germanic peoples east of the Rhine, it has also been considered one of the most decisive battles in history, and a turning point in world history." - (en.wikipedia.org 23.11.2021)
