Brennus was a Gallic chieftain known for leading the Gauls in their invasion of Rome in 390 BC. He is most famous for his victory at the Battle of the Allia, where his forces defeated the Roman army, leading to the subsequent sack of the city. This event marked a significant moment in Roman history, highlighting the vulnerabilities of the early Republic. The name Brennus is also associated with various historical figures and legends in Celtic culture. In addition to the Gallic leader, the name appears in different contexts, often symbolizing bravery and resistance against powerful adversaries. Brennus remains a notable figure in discussions of ancient military history.