The great Roman Empire had many enemies during its long rise and fall among them the legendary Attila, Alaric, and greatest of all, Hannibal (image on coin) who defeated the legions at Cannae in 216 BC.
Hannibal showed the mastery of the combined use of infantry and cavalry for which he was famous to surround and annihilate a huge Roman army. Of perhaps 70,000 Romans, only 14,500 survived to be taken prisoner at the end of the day. It is the greatest number of casualties suffered in a single battle by any western army before or since.
In the long run, he never received enough reinforcements to threaten Rome itself despite his army surviving in Italy for over a decade. In 183 BC, he committed suicide by taking poison to prevent himself being handed over to the Romans. Posted by Casey Kazan.