After making his historic crossing of the Alps with elephants transporting supplies and troops, Hannibal (Victor Mature) marches on Rome in a war of revenge. During his advance, he captures Sylvia (Rita Gam), the niece of Roman Senator Fabius Maximus (Gabriele Ferzett) but, instead of holding her prisoner, he shows her his powerful army and herds of elephants, then sets her free. He is sure she will report what she has seen to his Roman enemies. Hannibal defeats the Romans at the battle of Trebbia and sends a message to Sylvia that he is marching on Rome. Sylvia succumbs to her love of Hannibal and they have a rendezvous, but are surprised by a Roman patrol. Hannibal escapes and Sylvia is confined to the temple of the Vesta Goddess. She escapes and meets Hannibal again. Hannibal orders his brother Hasdrubal (Rik Battaglia) to Carthage to take over command of the reenforcements preparing to join Hannibal. Hannibals wife Danila (Milly Vitale)arrives from Carthage unexpectedly and Sylvia runs away and returns to Rome, where she is tried for high trteason and sentenced to death. Hannibal continues to fight but he knows he will not succeed in destroying Rome.