Rome was suspicious of Hamilcar’s intentions in Spain so they formed an agreement with the Spanish city of Sagantum. In turn, Hamilcar’s son Hannibal saw this move as a threat and laid siege to Sagantum in 219 BC. Rome gave Hannibal an ultimatum to surrender, he refused and the second Punic war broke out in 218 BC. Hannibal realised his only way to defeat the Romans was to get some of the Italian tribes comprising the Roman Republic to defect, which meant attacking Italy itself. However, he could not do it by sea because of the strength of the Roman navy. Hence his audacious plan to take an army across Spain, Southern France and the Alps to arrive in the Po valley in 218 BC with 20,000 soldiers (Spanish, African and opportunistic Gauls), half the number he started with and less than half the original 38 war elephants. Not imagining an attack from the north was possible, Rome had already sent an army to Spain and another to North Africa. They quickly mustered a further army but Hannibal crushed it. In one battle alone, by Lake Trasimene, Central Italy, 15,000 Roman soldiers were lost. Rome was exposed, but Hannibal’s purpose was to stir up trouble in the southern tribes, gaining extra troops, so that is where he led his army. He met reluctance from the southern tribes and downright rejection from the Greek cities. In 216 Rome sent another army of some 60,000 soldiers, but Hannibal’s tactics overcame them and many were killed. Hannibal besieged Tarentum and took it, but Rome regained it in 209 BC. In 207 BC Hannibal’s brother, Hasdrubal, brought another large army overland into North Italy to join Hannibal’s planned attack on Rome. The Romans managed to raise two further armies, the one moving north defeated Hasdrubal’s army, killing him, and his head was tossed into Hannibal’s camp as a warning. Because of the enormous cost of waging the war, Rome’s allies started to complain and there were no further significant battles in Italy. Hannibal was ordered to withdraw from Italy by sea around 203 BC as a Roman army headed by General Scipio had attacked Carthage in 204 BC, and the Carthaginian army in North Africa had been defeated. In 202 BC Hannibal led his army against Scipio and he too was defeated. The subsequent peace treaty confirmed Carthage’s loss of Spain (the Carthaginians were ejected from Spain in 206 BC), together with the loss of any remaining Mediterranean islands. Rome’s success was down to sheer persistence against all their adversaries, including Hannibal’s individual flair.

In parallel with fighting the Carthaginians, Rome had to send an army to Greece to prevent Philip V of Macedonia helping Hannibal. They also had to defend their territory in Sicily against Syracuse, whose son Archimedes devised many cunning contrivances to thwart them. By 210 BC Sicily was back under Roman control and Syracuse became the chief city in the Roman Province of Sicily. From 200 BC the Gauls invaded Northern Italy. The Romans resisted their incursions for 50 years before the Gauls were finally driven out.

At the start of the 2nd century BC, Rome’s eyes turned east against Philip V who they had defeated in 197 BC. The Seleucid leader Antiochus III, who had plotted against Rome with Philip, given refuge to Hannibal in 195 BC and invaded Greece in 192 BC, was driven out in 191 BC at another major battle at Thermopylae. The Romans then attacked Antiochus in Anatolia and by 189 BC had driven him east of the Taurus Mountains. Perseus became leader of the Macedonians in 179 BC causing unrest in the region, provoking Pergamum to complain to Rome, leading to Perseus’s defeat in 168 BC and Rome splitting Macedonia into four independent republics. Rome manipulated many events in Eastern Mediterranean, declaring war on the Achaeans in Greece in 146 BC because they “ill-treated Rome’s ambassador”. Corinth was sacked, its treasures taken to Rome and its buildings burnt down. Greece was annexed as a province that year, but Greek culture continued its influence for at least another 100 years.