Scipio Africanus and Hannibal the Great.
During the Second Punic War (218-201 B.) Hannibal the Great led Carthage to convincing victories over the previously invincible Roman armies. Rome was faced with a crisis. With the rise of Hannibal and with him Carthage, Rome turned to a young general named Publius Cornelius Scipio Africanus to put an end to Hannibal's terror. Unlike his predecessors Scipio studied Hannibal and used Hannibal's own strategy to out maneuver the Carthaginian army. Scipio prevailed over Hannibal, eventually defeating the Carthaginians at the battle of Zama. With this victory Scipio surpassed Hannibal as the greatest military genius of the Ancient World. .
Rome had won the First Punic War (264-241 B.C.), but failed to completely suppress Carthage. Shortly after the end of the First Punic War "Hamilcar Barca, a distinguished Carthaginian general of the First Punic War, devoted the remainder of his life to building up the Carthaginian power in Spain to compensate for the loss of Sicily." Barca's son, Hannibal eventually became the commander of the Carthaginian forces. Under Hannibal's command Carthage rose from defeat to once more to test the power of Rome. .
Through the use of unconventional strategies the Carthaginian army quickly took advantage of Rome. Hannibal saw that it would be a difficult task to attack Rome head on. Instead he elected to cross the Alps and attempt to catch the Romans by surprise. Against all odds Hannibal's troops "including several thousands of men, with its cavalry, supply corps, and elephants," successfully crossed the Alps. Never before had such an audacious attack been made upon the Romans. The Carthaginians took the Romans by surprise and forced Rome to abandon its invasion of Africa in order to deal with this new unanticipated threat.
The Roman army was unprepared to defend against a surprise attack from the north. Hannibal won major victories at Lake Trasimeno and the town of Cannae and was able to reach southern Italy.