Hannibalic War (2.9-2.10)

Thus had the Romans divided their large armies at this juncture for many campaigns. Hannibal, learning this fact, moved secretly in the early spring, devastated Etruria, and advanced toward Rome. The citizens became greatly alarmed as he drew near, for they had no force at hand fit for battle. Nevertheless, 8000 of those who remained were brought together, over whom Centenius, one of the patricians, although a private citizen, was appointed commander, there being no regular officer present, and sent into Umbria to the Plestine marshes to occupy the narrow passages which offered the shortest way to Rome. In the meantime Flaminius, who guarded the interior of Italy with 30,000 men, learning of the rapidity of Hannibal's movement, changed his position hastily, giving his army no chance to rest. Fearing for the safety of the city and being inexperienced in war (for he had been wafted into power on a popular breeze), he hastened to engage with Hannibal.

The latter, well aware of his rashness and inexperience, moved forward and took a position with a mountain and a lake [Thrasimenus] before him, concealing his light-armed troops and his cavalry in a ravine. Flaminius, seeing the enemy's camp in the early morning, delayed a little to let his men rest from their toilsome march and to fortify his camp, after which he led them straightway to battle, although they were still weary with night-watches and hard labor. Caught between the mountain and the lake and the enemy (for the ambush suddenly appeared everywhere), he lost his own life, and 20,000 men were slain with him. The remaining 10,000 escaped to a village strongly fortified by nature. Maharbal, Hannibal's lieutenant, who had himself acquired very great renown in war, not being able to take them easily and thinking it unwise to fight with desperate men, persuaded them to lay down their arms, agreeing that they should go free wherever they pleased. When they had complied with this agreement he brought them disarmed to Hannibal. The latter, denying that Maharbal had authority to make such an agreement without his consent, nevertheless treated the Roman allies with kindness and sent them home without ransom, in order to conciliate their towns. He kept all the Romans as prisoners. He gave the booty to the Gauls who were serving with him, in order to attach them to him by the hope of gain, and then marched forward. When this news reached the consul Servilius on the Po, he marched to Etruria with 40,000 men. Centenius, with his 8000, had already occupied the narrow passage previously mentioned.