4.20
Hannibal had previously observed that a stormy east wind began to blow in that region regularly about noon. So he chose the ground where he should have the wind at his back. Then on a wooded hill cut by ravines he placed some cavalry and light-armed troops in ambush, to whom he gave orders that when the battle was joined and the wind had risen, they should fall upon the enemy’s rear. With them were placed 500 Celtiberians who had, in addition to the long swords at their belts, short daggers under their garments. These they were not to use till he himself gave the signal. He divided his whole army into three lines of battle and extended his horse at long distances on the wings in order to outflank the enemy if possible. He gave the command of the right wing to his brother Mago, and of the left to his nephew Hanno, retaining the centre for himself on account of Aemilius’ reputation as an experienced commander. He had 2000 picked horse and Maharbal had 1000, who were ordered to move about and give assistance wherever they saw any part of the army in difficulties. In making these arrangements he protracted the time till about the second hour so that the wind might come to his aid the sooner.
