top of page
Writer's pictureEA Baker

What-if Scenarios: Hannibal Sacks Rome

After spending a long time in World War I, I decided to make a radical change for my next alternate history scenario. Inspired by my recent read, In the Name of Rome: The Men Who Won the Roman Empire by Adrian Goldsworthy, I decided to jump back in time to the Second Punic War. 


Anyone who has studied military history probably has heard the name Hannibal, the famed Carthaginian general and statesman. Known for his invasion of the Italian Penisula over the Alps with an army containing 37 war elephants, Hannibal delivered three back-to-back defeats to the Roman Republic. Yet, he never attempted to besiege or sack Rome itself. 


In this scenario, I will explore Hannibal's invasion, his trilogy of victories, and why he didn’t march on Rome when he had the chance. Then, I’ll explore the scenario of him besieging or marching on Rome, what circumstances would’ve made this more feasible, and the repercussions if he decided on this course of action. First, let’s set the stage. 


The Second Punic War


In 218 BC, Carthage and Rome were the two main powers in the Mediterranean. After losing the First Punic War against Rome, Carthage sought to expand its holdings in the mineral-rich region of Iberia, again leading to a confrontation with Rome. After Hannibal sacked the pro-Roman city of Saguntum, the two powers were at war. 

Map showing the key marches and events of the Second Punic War.
Map of key marches and events of the Second Punic War.

Hannibal, son of Hamilcar Barca, who commanded Carthaginian forces in the First Punic War against Rome, had pledged to his father that he “would never be a friend of Rome.” After sacking Saguntum (modern-day Sagunto, Spain), Rome declared war, and Hannibal marched on Italy. That was a task easier said than done. 


Hannibal’s Land Crossing


With an unwieldy force (by the standards of ancient times) of approximately 91,000 infantry and cavalry, Hannibal departed New Carthage (Cartagena, Spain) to invade the Italian peninsula. However, he did not have an easy path. Along the way, he had to outmaneuver and contend with the Celtiberian and Gaulish tribes. 


The Pyrenees stood as his first land obstacle. The crossing was not a peaceful march but involved battles with the local tribes. Yet, he could get across, leaving his brother Hanno and 12,000 troops (take all numbers with a grain of salt, given I’ve seen them varied) to guard the passes to his army’s rear as they marched forward. He also had to release another 15,000 troops who were threatening revolt (sources say they didn’t want to leave their homeland of Spain; others say they didn’t like their destination of Gaul). 



When Hannibal marched into Gaul, he had 55,000 infantry, 9,000 horses, and 37 elephants (other sources say 40,000 infantry, 12,000 horsemen, and 38 elephants). Considering the terrain he had to cross and the tribes he had to deal with, Hannibal made good time, leaving in spring and arriving on the banks of Rhȏne 45 miles up from its mouth by September, covering roughly 640 miles. 


At this time, the Roman Republic was functioning under the Duel Consul system. The Consuls elected for the year were Publius Scipio and Tiberius Longus. Each cast lots for their assignments, resulting in Scipio getting Spain and Longus getting Africa. The Senate had decided to launch a two-pronged attack against both Carthaginian holdings, but due to internal strife, departures were delayed until midsummer. 


Artistic representation of Hannibal crossing the Rhône.
Hannibal crossing the Rhône.

Scipio initially stopped at Marseilles on his way to Spain. But after he learned Hannibal had crossed the Pyrenees and was approaching the Rhȏne, he deployed his legions on the river's east bank. After both launched scouting parties to determine where each army was camped, Scipio’s scouts found the Carthaginian camp and reported back. They were gone when Scipio received the report, deployed his forces, and marched on the Carthaginians. Hannibal had slipped away. 


Over the Alps 


After defeating a Gaulish ambush as he crossed the Rhȏne, Hannibal dared the unthinkable by attempting to cross the Alps in late October. After failing to bring Hannibal to battle, Scipio retreated to northern Italy to wait for him. But they thought they had more time to prepare, given that they didn’t think he would attempt a crossing so late in the year. 


Constantly harried by tribes, extreme alpine weather, and threats of mutiny, Hannibal made it across the Po Valley in four weeks with half his army intact. Scipio, and all of Rome for that matter, were shocked that he successfully crossed. Sending them into a panic, Scipio called for Longus to return (he was currently in Sicily on his way to Africa) and join forces to defeat Hannibal. Scipio didn’t wait, moving north and encamping near Ticinus. 


Subsequent Defeats 


The first engagement was with Calvary and ended in a Roman defeat after the Carthaginians outflanked them. Scipio was also wounded in the engagement, which resulted in several things. First, Scipio decided to retreat back across the Po to wait for Longus to join his force. Second, the victory won over Gaul's auxiliaries to leave Scipio’s force and join Hannibal. He also could recruit more Guals who were not friendly to Rome to his side, replenishing his losses from the Alps crossing. 

Battle map showcasing the movements and dispositions of Roman and Carthaginian forces during the Battle of Trebia.

Longus was anxious to attack Hannibal with the upcoming Consul elections when he joined Scipio. Yet, Hannibal chose to attack first. Using his elite Numidian horse under the command of Maharbal, he attacked the Roman camp. Meanwhile, Hannibal positioned his force on high ground while he sent his brother, Mago, with 2,000 troops to conceal in the bushes on the flank. When the Romans chased across the Trebia, they met Hannibal’s main force before they were taken in the rear by Mago’s hidden force. The Romans were met with defeat yet again. 


Two New Armies and Failures


Two new Consuls were elected in 217, and two new armies were formed. Gnaeus Servilius was assigned to guard the approach through Ariminium on the Adriatic, while Gaius Flaminius covered the road to Rome from Arretium. Hannibal would again prove his adeptness as a maneuverer, bypassing both armies as he moved west to Colina before crossing the Apennines and descending into Arno's marshes. 

Battle map showcasing the Roman march and Carthaginian attack during the Battle of Lake Trasimene.

Moving to the north shore of Lake Trasimene, Hannibal set an ambush for the Romans. Flaminius marched his legions along the lake in a long column. Hannibal attacked its left flank, slaying some 15,000 legionnaires in only an hour, with a similar number taken prisoner. Hannibal turned his army to face Servilius, but to his good fortune, Maharbal horseman had already defeated the 4,000 Roman scouting horses. This blinded Servilius’s army, forcing him to remain in place until he could replenish his calvary. 


From Dictator to Cannae 


Panic ensued after losing two more armies, and Rome elected a dictator by popular vote for the first time in its history—Quintus Fabius. He approached Hannibal differently, deciding to strengthen the walls of Rome, burn the bridges over the Tiber, raise a new army, implement a scorched earth policy ahead of Hannibal’s advance to stress his army’s resources, and wait out Hannibal rather than engage directly. This approach became known as the Fabian Policy. 


Yet, despite these measures, Hannibal continued to find ways to survive, but winter was approaching. With a knack for understanding his opponent, Hannibal was able to outfox Fabius the Delayer, seizing Geronium and a large grain store before fortifying his position to settle in for winter. 


The Roman Senate had grown weary of the Fabian Policy, citing numerous failures in their eyes, the latest being Hannibal’s evasion that set his army up for winter. They returned to the two-consul system and elected  Aemilius Paulus and Terentius Varro. At the same time, Hannibal had exhausted the stores at Geronium, moved south across the Aufidus, and seized Cannae. With 80,000 men at their back, Paulus and Varro moved south to deal with Hannibal. 

Battle map showcasing the Roman defeat at Cannae.

Despite their numbers, the battle would not go the way the Romans wanted. Hannibal’s superior horseman dealt with the Roman cavalry on the flanks. At the same time, as the main Roman body hammered against the convex formation of Hannibal’s main body, the outward arc of the front line became flat before becoming concave. As Hannibal's light Numidian calvary ran down the retreating Romans, his heavy calvary regrouped and smashed into the Roman rear. Then Hannibal’s flanks reeled inward, achieving a double envelopment of the Roman army; their fate was sealed. 


After two hours of battle, the Romans lost 65,000 of their host, while the Hannibal lost less than 7,000. Despite this, the Romans would fight for 14 more years until Hannibal was defeated at the Battle of Zama, refusing to surrender, probably to the exasperation of Hannibal. But after Cannae, why didn’t Hannibal march on Rome? And was sacking it even feasible? 


Hannibal Marches on Rome?

There were reasons why Hannibal did not march on Rome in our timeline. We must first explore these to explore a scenario in which Hannibal decides to march on Rome.


  1. Spain Over Italy


    Hannibal’s brother Hasdrubal lost the Battle of Dertosa in Spain. Spain was rich in minerals and was a priority to the Carthaginian Senate more than Italy. As such, Carthage sent thousands of reinforcements to Spain while Hannibal received a mere token force. Had Hasdrubal not lost at Dertosa, perhaps the Senate would’ve sent Hannibal more reinforcements. 


  2. Rome’s Strong Navy 


    Hannibal had many logistical challenges. For that reason, he needed to find ways to keep his army resupplied, which involved foraging and trying to forge alliances in Italy. That was largely because Rome’s navy controlled the waters off the coast. However, Carthage did manage to reinforce his army, albeit with a small force. It’s debatable if they could have funneled a much larger force to him if they weren’t diverted to Spain. 


  3. Divided Carthage


    To obtain support, Hannibal had to send his brother Mago back to plead for aid. The Carthaginian elite was divided over Hannibal’s incursion from the war's outset. As I mentioned above, they worried more about losing Spain than taking Italy and defeating Rome. 


Considering these factors, it seems Hannibal probably would’ve been better served building stronger support for his invasion beforehand. But for the purposes of this what-if scenario, let’s assume everything remains the same except for two key changes. Both of which focus on his brother Hasdrubal. 


The Battle of Dertosa was significant in that it prevented Hasdrubal from reinforcing Hannibal and redirected reinforcements to Spain that Hannibal could’ve used. Dertosa was strikingly similar to Cannae, except the Carthaginian center folded, Hasdrubal’s calvary did not win the battle of the flanks, and he misused his elephants. 


The second opportunity was Hasdrubal’s next attempt to link up with Hannibal. Unfortunately, he met disaster at the Battle of the Metaurus. Hasdrubal would meet his end along with more than half his force. Hannibal’s other brother, Mago, would also attempt an invasion, sacking Genoa. But the Romans deftly kept them isolated from each other. In the end, Hannibal would stand alone.  


The Danger of a Siege 


Hannibal was no fool. He knew he would force a battle if he marched on Rome with or without reinforcements. While he would have the advantage of seizing the initiative and forcing the Romans to come to meet him (assuming Fabius does not continue to delay), it would most likely be between a Roman army and the walls of Rome itself unless he intercepts the Romans elsewhere. 


Yet, Hannibal’s greatest underestimation was Rome’s willingness to fight despite unprecedented defeat. Reading about these victories, I often wonder if Hannibal was shocked that Rome did not use it for peace (most city-states would’ve after Cannae). Perhaps that was something he had not anticipated. Regardless, the Romans continued to fight, stretching the war out until Hannibal finally returned to Africa, where Scipio defeated him. 


If the stars had aligned and Hannibal had received reinforcements, he might have considered laying siege to Rome. If that had been successful, history would’ve taken a different trajectory. Perhaps Italy would’ve become a Carthaginian colony until another power could challenge them. 

But most of all, without Rome, so much would change. Religion (Christianity and its influence were critical in shaping the West through the Romans), language (languages would’ve had more Phoenician influence rather than Latin), and more would alter everything we've learned about the history of the West. 


Since my blog focuses primarily on military history, it would be an oversight not to say how Rome influenced much of the world’s martial psyche. Patton believed he had fought in a past life as a Roman legionnaire. The Roman Empire deeply influenced Napoleon. And even the Nazis looked back, admired, and manipulated Roman history to their own evil ends. The tentacles of Roman influence run deep throughout history. If Hannibal had defeated Rome, it could’ve had lasting ripples that we would see today. 


Ad for The Kaiser's Machines WW1 alternate history series out now on Amazon.

Sources:

Goldsworthy, Adrian. In the Name of Rome: The Men Who Won the Roman Empire. London, Weidenfeld & Nicolson, 2004.


Images:

Comments


Commenting has been turned off.
bottom of page