Arminius (/ɑːrˈmɪniəs/; 18/17 BC – 21 AD) was a 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 precipitated the Roman Empire's permanent strategic withdrawal from Germania Magna, and modern historians regard it as one of Rome's greatest defeats.