The Second Punic War was a conflict that was fought from 218 to 201 BC between the Roman Republic and Carthage. Most of Carthaginian forces were led by Hannibal Barca. He scared the Romans by invading them over the mountains from Hispania with war elephants. He won the Battle of the Trebia and kept winning battles by being a good general. In the Battle of Cannae, he destroyed with his small army the largest army that the Romans had ever used.
The Romans then avoided fighting Hannibal and concentrated on defeating his allies. That became known as the Fabian strategy. Each side had many allies. However, most of Rome's allies stayed loyal, but Carthage's allies switched sides.
The Second Punic War ruined the power of Carthage. Rome became the dominant power in the Mediterranean for the next 600 years.