In 218 b.C., while several issues still had to be addressed in the relationships between Rome and the Greek cities of southern Italy, Hannibal crossed the Alps, thus bringing the war against the Romans directly to Italy.

As we know the advance of the great Carthaginian leader seemed unstoppable and after the terrible defeat inflicted upon the Romans at Cannae (216 b.C.) the fate of Rome seemed already sealed. Thus began the defections of all those cities of the southern Italy which, during the period between the two wars, started to consider the Romans as an occupying force rather than allies and willingly decided to side with the Carthaginians, also incited by the constant promises of freedom and independence that Hannibal made them.

Soon Apulia, Lucania and most of Campania fell under Carthaginian control; to complete the conquest of southern Italy by now Hannibal just needed the Bruttium, and against it he turned his attention during the winter between 216 and 215 b.C.
Hannibal thought that it was a priority to obtain as soon as possible an access to the sea in the Bruttium and, after giving up to conquer Rhegion, he ordered to his lieutenant Hanno the Elder to take control of Locri.

The news that the Carthaginian army was marching toward the former Greek colony forced the Locrians to try to get from their territory as many resources as possible in order to take refuge within the walls and thus trying to resist the already unavoidable siege. But Hanno the Elder, informed about such try, sent forth the cavalry under the command of his officer Hamilcar with orders to lock outside the city walls the people intent on recovering those resources recommending, however, to avoid harming anyone thus ensuring himself a large number of prisoners.

The plan of the Carthaginian commander was successful and the prisoners were used as a bargaining chip to obtain the unconditional surrender of the city that immediately, by accepting the exchange, could enjoy the Carthaginian protection and friendship.

The Locrian popular assembly, convened to decide on the response to give to Hanno, though reluctant to surrender to the Carthaginians, in the end gave his assent to the exchange, especially fearing for what could have been the fate of their relatives held captives.

At the same time, however, partly to avoid an offence to the former ally during an age with an uncertain future and partly because the Locrian people, since the return to the city of the garrison in 272 b.C., never had problems with the Romans, it was secretly decided to let the same garrison, commanded by Lucius Atilius, to leave the city by sea to reach Rhegion and joining there the other Roman troops, thus escaping the Carthaginian fury.

This action nearly put an end to the agreement with the Carthaginians; however, in the end, Hannibal gave orders to his lieutenant to keep his word.

Thus to the city of Locri was granted a large autonomy by keeping under its control the harbor and by being able to govern itself provided that, if necessary, would have provided a valid support for the Carthaginian forces. (Livy, Ab Urbe Condita, XXIV 7, 1-13)

This new relationship that was established between Locri and the Carthaginians allowed during the same year (215 b.C.) some Locrian messengers, after obtaining permission from Hanno, to offer a chance of salvation to the Krotonian "brothers" (the clashes of the Greek age are, by now, just distant memories) besieged by the Bruttii and by the Carthaginians in the last unconquered bastion of their ancient and powerful Greek colony.

The agreement that the messengers had stipulated with Hanno lied in the offering to the besieged Krotonians of the possibility to leave their city and to move, safely, to Locri. The Krotonians accepted and Kroton fell into the hands of Carthage. Such episode is handed down by Livy (Ab Urbe Condita, XXIV 3, 14-15), although there are some doubts as to whether, after the abandonment of Kroton, the exiles have been actually transferred en masse to Locri.

After the conquest of Locri and almost every other city in the Bruttium and after the extremely important taking of Taras, Hannibal seemed now ready to launch the decisive attack against Rome. But that did not happen and the Roman forces began to obtain their first major victories, starting with the accomplishment made by the troops under the command of the consul Marcus Claudius Marcellus, which were able to conquer Syracuse marking the beginning of the Roman redemption after many years in which the Carthaginian army seemed invincible.

One after another the cities of southern Italy conquered by the Carthaginians or came up against Rome were taken back by the Romans. And after reconquering Taras the Romans put their eyes on Locri, the last major city of the ancient Magna Graecia still in the hands of Hannibal.

The effort, however, immediately proved difficult for the Romans so much so that the ground troops sent to support a naval expedition led by Lucius Cincius Alimentus were shattered at Petelia causing the loss of nearly 3500 men (2000 deaths and nearly 1500 prisoners). Shortly after even the two Roman consuls, Marcus Claudius Marcellus and Titus Quinctius Crispinus, were killed during a recognition mission near the Carthaginian encampments.

In the meantime, however, the naval expedition of Lucius Cincius Alimentus reached Locri besieging it. Hannibal immediately gathered his troops and marched to Locri. Within the besieged city there was the Carthaginian garrison commanded by Mago who, seeing his commander coming to bring him help, decided to launch a furious attack against the besieging Roman troops that, surprised by the reaction of Mago and frightened by the arrival of Hannibal, fled on board of the ships with which they had come.

Thus ended the siege of Locri, it's the 208 b.C.

The following was a significant year for the future of the war. The Romans, in fact, killed Hasdrubal, Hannibal's brother, cutting off the chance for the Carthaginians of receiving supplies; at the same time they reconquered Metapontum and Heraclea leaving by now in the hands of Hannibal only the cities of the Bruttium with Locri as his latest major city and stronghold. Nevertheless, the situation for the ancient polis was relatively quiet until 205 b.C.

In that year the console Publius Cornelius Scipio (Scipio Africanus) himself took care of the plans to reconquer Locri, and the right opportunity presented itself when some Locrian citizens fell into the hands of the Romans. The captives informed the Romans of the fact that by now a large part of the population could no longer bear the Carthaginian occupation and that, if properly prepared, could have turned against the occupants and could have opened the city gates to the old ally. Such words confirmed to Scipio by the Locrian exiles of Rhegion, loyal to Rome, started an effort which consisted in letting the captives return to Locri where they, once within the walls and during the night, would have disarmed all the Carthaginian guards, thus allowing an easy entry into the lower part of the city for the Roman troops (three thousand men) commanded by the military tribunes Marcus Sergius and Publius Matienus, under the supervision of pro praetor Quintus Pleminius; and that's what happened.

The Carthaginians, caught off guard, moved into the upper part of the city and thus began an exhausting battle, made up of never decisive daily skirmishes, between the two enemy garrisons inside the city: on one hand the Romans led by Quintus Pleminius and on the other hand the Carthaginians led by Hamilcar.

Upon learning of the situation Hannibal immediately set in march with his army to reach Locri. He was already about to reach the city when, however, the same Locrian population, lately victim of the harassment and of the oppression of the Carthaginians, took the field alongside the Romans, that seemed by now overwhelmed, thus changing in their favor what could have been the fate of the battle.

Here is how the episode is reported by Livy (Ab Urbe Condita, XXIX 6, 17):
 

After a short while the Roman fleet came, led by Publius Cornelius Scipio himself, who started to disembark his troops to give a hand to the men who were already inside the city. So Hannibal realized that Locri was already lost. Therefore he ordered to his men, that still were inside the city walls, to try to flee in whatever manner and, after ordering that, he too went away.

After ten years Locri was again under Roman control and was about to experience a time of violence and cruelties due to the arrogant and overbearing administration of Quintus Pleminius, which will be described into details in the next chapter.

The Roman recapture of the 205 b.C. concludes the military events that involved Locri during the Second Punic War and, in two years, the war itself came to an end with the departure of Hannibal and the final victory of Rome.