Arminius
Arminius, also known as Armin or Hermann (b. 18 BC/17 BC in Magna Germania; d. AD 21 in Germania) was a chieftain of the Cherusci. He was able to unite a group of Germanic tribes together to fight the Romans. They destroyed a Roman army in the Battle of the Teutoburg Forest. This was the greatest military disaster the Romans had ever suffered.