On this day in 217 B.C., the Romans are ambushed and defeated by Carthaginian commander Hannibal Barca at the Battle of Lake Trasimene.
At the end of 218 B.C., Hannibal Barca was reaching the zenith of his career. He had just defeated the Romans at the Battle of Trebia, sending shockwaves throughout the Roman Republic. The Senate was in shock, that battle had showed that not only could the Carthaginians defeat the Roman cavalry, but their legions as well!
Nevertheless, when the Senate entered the new year (the Battle of the Trebia took place during the Winter Solstice of 218 B.C.) they were determined to finish the war with greater success than so far.
The other theaters of the war weren’t ignored, but the Roman war effort were primarily focused against the enemy in their own territory, and both consuls that year were ordered to march north to face Hannibal. The two consuls were Gnaeus Servilius Geminus and Gaius Flaminius. It is not known exactly how many Romans and allies were enlisted in the armies, but it appears that the armies were stronger than usual, especially when it came to the number of cavalry (which would seem to be a logical response to the overwhelming superiority of the Carthaginian cavalry).
Polybios’ story tells that little activity took place during the winter, and while Polybios usually was a fairly neutral party (with obvious pro-Hannibal leanings though, or rather, anti-Roman leanings) he does tell a story about how Hannibal, unsure about the loyalties of his new Gallic allies, dressed up in many different costumes to spy on them, but it doesn’t sound very plausible, and is probably just a story made up to show the cunning and suspicious nature of Hannibal.
When spring came, and the time for campaigns had begun, Hannibal had two realistic options. He simply could not remain idle in the Po valley, for eventually the consuming of the supplies in this region, would whittle down support from the Gauls and of course allow the Romans to recover from the shock and attack in strength. He could potentially move into Liguria, but that wouldn’t weaken Rome much, and it would be difficult to gather supplies there.
Therefore, out of the two options, only one remained: Continue pushing south. This option demanded that Hannibal paid attention to the most important feature in Italian geography: the Appenine mountains, cutting the peninsula in half and leaving precious few routes for an army to cross. Because of that, Hannibal could now either march east towards the Adriatic Sea and continue along the coast until he hit the region of Picenum, or go south towards the passes across the Appenines and march into Etruria (today part of Tuscany, Lazio and Umbria).
Since this was obvious to Hannibal, it was also obvious to the Roman Senate, who deployed their consuls to counter both options: Gnaeus Servilius Geminus took up positions in Ariminum (modern Rimini) to cover the east coast, while Gaius Flaminius went to Arretium (modern Arezzo) to cover the mountain passes into Etruria. Gaius Flaminius would play a lead role in the coming campaign and he has been badmouthed in existing sources because of his failures (Flaminius died at the Battle of Lake Trasimene and as such was in no position to defend himself against his accusers). He wasn’t from a noble family, and had few heirs to challenge the perception of him.
In short, Flaminius was a “homo novus”, the first from his family to rise to become a consul. Polybios and (especially) Livy agree that Flaminius was an aggressive demagogue, a man of big words but small intellect who pleaded with the masses in order to gain power in the Senate.
As soon as spring arrived, Hannibal began moving his army. As usual, he moved quickly and in an unexpected direction. He had decided to cross into Etruria, partly because the area was fertile enough to support his troops, but also because that route posed a more direct threat against Rome (remember, if he had decided on the other route, the central parts of the Appenines would stand between him and the city of Rome). He probably marched through the Porretta- or possibly the Collinepass and paved his way through the marshes around the river Arno.
He pushed his troops hard to get them through this difficult terrain quickly. His most disciplined troops, the fast-marching Africans and Iberians walked in the front with the supply train and marched in a speed that the inexperienced Gauls had trouble matching. Hannibal kept his cavalry in the rear where they “encouraged” the Gauls to move faster. It took them three days and three nights to cross the marshes, and while he lost quite a few troops because of the conditions there, he had once again managed to cross a major obstacle, without the interference of his enemies and he was now ready to implement the next phase of his plan.
He gave his men a couple of days rest, and during that time he sent out scouts to locate the Romans and gather as much intel as possible about the surrounding area. When he learnt that Flaminius was at Ariminum, he decided to bypass the Roman army hoping to lure them further south, which if successful would make it harder for the other consul, Geminus, to get his troops there in time (Hannibal had no way of knowing where Geminus were, but he was certain that as soon as the Romans found out which way he went, they would immediately send for reinforcements).
Other factors also made this plan both doable, and desirable. Hannibal had no permanent supply base yet, which meant that he had no supply line that the Romans could cut off. Instead he relied on the territory he marched through to feed his soldiers, which in any given situation is a risky tactic but here in Italy it worked.
Still, since his supplies would run out rather soon, Hannibal’s decision to try and lure his enemy into battle AND defeat them before his troops began to starve was a gamble. Hannibal simply did not have the resources or men for a large number of small skirmishes and tied battles.
And boy, did Flaminius take the bait, he acted just like Hannibal knew he would, because he acted just like any other Roman consul in his place would have done. As soon as he realized that the Punic army had moved past him and started raiding and pillaging that belonged to Roman allies, he marched out of Arretium to begin pursuing his enemy. (Here, our sources begin talking about how Flaminius ignored all his officers and their advise for caution, and he also ignored several omens, like his horse throwing him off and that the standard-bearers had trouble getting the standards out of the ground, but this is likely just propaganda to make Flaminius look bad.)
As the Romans marched south, they passed through devastated villages, which was incredibly humiliating for the Romans, to not be able to stop an enemy from violating their territory and that of their allies, and this had a negative effect on the soldiers. It is important to note that the Roman army still consisted mainly of recruits levied from the countryside, farmers and their sons, commander by officers who owned land in the countryside. When an enemy openly ignored a Roman army and instead began plundering and looting the surrounding area, it was a direct challenge to the Romans.
It was as if Hannibal had sent them a note saying “We despise you, you can’t even protect your own land how are you supposed to defeat us?”, goading the Romans into action. Few, if any, states in the ancient world could stomach such an insult, and Rome was no exception.
Hannibal continued south, constantly provoking the Romans with his ruthless plunder and burning of the areas they went through. The Romans were now only one days march behind him. After Hannibal had passed the city of Cortona he reached Lake Trasimene, and here he saw an opportunity. The main path continued through a narrow passage, which the beaches of the lake on one side, and large hills on the other.
There, the Carthaginian army passed the lake and made camp where the hills ended. During the night, Hannibal divided his forces in several columns and led them behind the hills, where they took up positions that was parallel with the passage, hiding them from the enemy. Closest to the Roman army Hannibal placed his cavalry, ready to strike as soon as all enemies had entered the narrow passage, cutting off their retreat path. At dawn, on June 24, Flaminius and his army began marching. It was a foggy morning, and the shapes of the hills were just barely visible but it is possible that he saw the Punic camp at the end of the narrow passage. As the Romans marched along the passage, the Carthaginian troops showed a level of discipline that deserves our admiration.
Not until the Roman front reached the Carthaginian army did Hannibal order his hiding troops to attack. The Roman army was caught completely by surprise as the Punic warriors launched themselves upon their enemies from the hills. From the moment the trap was sprung, Carthaginian victory was never in danger, but it still took almost three hours to finish the battle, but all across the narrow passage Romans and Roman allies panicked and tried to flee from both real and imaginary enemies that appeared through the mist. Roman casualties was extremely high, out of 30 000 men around 50% of them were lost, while Hannibal only lost around 2500.
Polybios says that Flaminius panicked and became desperate until he was killed by a nameless Gaul, but Livy (who in all other situations did his best to badmouth Flaminius) gives Flaminius an end more fitting for a Roman consul. In his version, Flaminius galloped around his army, shouting words of encouragement and trying to organise a resistance. After gathering his most brave soldiers, he attacked where his troops were most in distress until he finally were killed.
After the death of Flaminius, the Roman army lost much of its cohesion and began to collapse. As the Romans fled and threw their weapons to lose weight they were killed and many drowned as they ran into Lake Trasimene trying to swim to safety. The Roman vanguard, realizing that even if they turned around and headed back to the battle, they could not avert disaster, continued forward until they reached a nearby village where they took refuge. Later that day Hannibal dispatched his cavalry commander Maharbal with a few Iberian troops escorted by spear men to surround the village. The vanguard surrendered after they had been promised that their lives would be spared and (according to Livy) that they would be allowed to keep the clothes they wore but nothing else. Hannibal did not like that deal though, so he countermanded his subordinates and instead took the Romans as slaves.
The Roman allies (who was in majority in the vanguard) were however allowed to walk free, as Hannibal assured them that he and the Carthaginians fought for them, against Rome. Quintus Fabius Pictor claims that 15 000 Romans died while 10 000 escaped eventually making it back to Rome. That number does not say if prisoners (like the 6000 slaves they took from the vanguard) are included in the 15 000 but Polybios claims that the number of prisoners also were 15 000. Hannibal also managed to capture a lot of military equipment, so his Libyan forces were soon equipped like the Roman legionaries.
The Carthaginians lost between 1500 and 2500 men depending on the source and most of these losses were newly recruited Gauls. Losing 3 – 5% on ones army in return for completely annihilating the enemy as a fighting force is a small price to pay. Few commanders have ever managed to repeat what Hannibal did: luring an entire army into an ambush and then destroy it. He had been in the driver’s seat this entire campaign and lured Flaminius into a hopeless situation. His soldiers showed an impressive amount of cunning and discipline, not only were they capable to get into ambush positions during the night, without getting lost and without alerting the Romans, but they also managed to remain in hiding until the time was exactly right.
This second disaster which happened just 6 months after the first disaster (the Battle of the Trebia), shock Rome’s very foundations. As the rumors spread, and the first survivors started arriving to the city, the praetor of Rome stood at the Forum, simply saying: “Pugna magna victi sumus” (“we have been defeated in a large battle”).