In the early morning of June 24, 217 b.C., under a thick layer of fog, the best part of the Roman Army was already stationed in the plains. Hannibal had positioned his light cavalry and the Celts at the entrance to the valley to block any possible Roman retreat; the Libyans and Iberians protected his camp; the Balearics and Asiati closed the way to the hill of Montigeto. Hannibal gave orders that they should all attack at the same time. The battle continued for three hours, and 15,000 Roman soldiers who sought escape in the waters of the lake were killed.