What are the four major Battles of the Second Punic War?
If you said, "Trebia, Trasimene, Cannae, and Zama", you are correct!
Prologue
In 218 BC, Carthaginian General Hannibal, with an army of 40,000 and more than 30 war elephants, crossed the Pyrenees Mountains, then crossed the Rhone River, and then crossed The Alps in winter, and invaded Northern Italy, otherwise known as Cisalpine Gaul.
Trebia River
In December, on a floodplain of the Trebia River, Hannibal decisively defeated a Roman Army led by Roman Consul Tiberius Sempronius Longus.
Hannibal's Numidian Cavalry were instrumental in victory, and the Carthaginian Light Infantry out-flanked the Roman Infantry. But the battle was decided when a hidden Carthaginian unit ambushed the Roman Army from behind while they were engaged.
Lake Trasimene
In the Spring of 217 BC, Hannibal crossed the Apennine Mountains, marched for four days through the swamps near the mouth of the Arno River (which flows through modern Florence and Pisa), and ambushed a Roman Army which was led by Roman Consul Gaius Flaminius, as it marched along the shore of Lake Trasimene.
This was (and still is), the greatest ambush in human military history. And once again the Roman Army was wiped out.
Cannae
Rome scrambled to rebuild it's army, and once again on August 2 216 BC, met Hannibal at the Battle of Cannae. This time the Roman Army was led by both Consuls: Gaius Terentius Varro, and Lucius Aemilius Paullus.
Once again, Hannibal had more and better Cavalry. However the Carthaginian Army was outnumbered by the Roman Army nearly two to one. But through clever and deceptive battle-field deployment and maneuver, Hannibal's more-experienced infantry managed to completely surround the Roman Infantry, which consequently fell-in on itself, and unable to fight or maneuver, was almost completely wiped out.
The Battle of Cannae was (and still is), one of the bloodiest days in human history with perhaps 50,000 - 70,000 casualties in the span of just a few hours.
Zama
By waging war against Carthage, Roman General Publius Cornelius Scipio compelled Hannibal to return with his Army to Africa, where the two met in 202 BC at the Battle of Zama.
This time Rome had the superior Cavalry as Numidia was now allied with Rome. Hannibal's 80 war elephants spooked and were inneffective.
At first, the Carthaginian Cavalry attempted to lure the Roman Cavalry away from the Battle Field by fleeing. However, Hannibal's tactic of placing his veterans in the rear back-fired, because about the time that the first two lines of Carthaginian Infantry were wiped out and the third line was engaged, the Roman Cavalry returned to the Battle Field and rolled-up the Carthaginians from behind.
Carthage was routed from the Battle Field and the fleeing troops were easily pursued and killed by the Roman Cavalry in the flat terrain. On the Ancient Battle Field, you were a winner ... until you were not.
Hannibal would regret not having attacked the City of Rome following the Battle of Cannae.
The Second Punic War earned for Rome the reputation of refusing to give up and refusing to accept defeat.