Throughout Rome's history, the Empire faced many formidable enemies and charismatic figures. Well, who do you think was the greatest of them all?
We've got Brennus, leader of a Senone Gaulish horde, who was the last person to sack Rome for 800 years.
Pyrrhus of Epirus, who fought the Roman Republic in Southern Italy as well as ousting the Carthaginians from Sicily at the same time. He is where we get the phrase "Pyrrhic Victory"
Hamilcar Barca (not Hasdrubal, sorry) who fought Rome during the First Punic War
Archimedes, a Greek scientist from Syracuse who created massive weapons of destruction to hold back the Romans.
Hannibal Barca who fought Rome in the 2nd Punic War, famous for crossing the Alps with his elephants, he crushed Roman armies on more than one occasion within their own homeland of Italy.
Philip IV of Macedon, who sided with Hannibal, he nearly re-unified Greece, which, according to the Romans, would have been the greatest threat possible.
Antiochus III fought Rome in Syria and Asia Minor, managed to reform the Seleucid Empire quite a lot during his reign.
Vercingetorix leader the first and only unified Gaulish war against Rome, he faced off against Julius Caesar (defeating him at Gergovia), and invented scorched-earth tactics.
Boudicca, the only woman on this list, she led a massive rebellion in Britain (home of several notable Roman figures, such as Constantine the Great) against Roman rule
Ermanius (or Arminius) slaughtered Roman legions in Germania at Teutoburg Forest, affectively halted Roman expansion into the region.
Alaric King of the Visigoths, sacked Rome in 410, the first time in 800 years!
Attila the Hun the Scourge of the West, was thought to be God's retribution on a decadent people. He built an empire from almost nothing and threatened Rome, defeating Rome on multiple occasions, and was only turned back from destroying the Eternal City itself by a bribe from Pope Leo the Great