weeks; sometimes forming up in battle order each day. In such circumstances either commander could prevent a battle from occurring, and unless both commanders were willing to at least some degree to give battle, both sides might march off without engaging. Forming up in battle order was a complicated and premeditated affair, which took several hours. Infantry were usually positioned in the centre of the battle line, with light infantry skirmishers to their front and cavalry on each flank. Many battles were decided when one side's infantry force was attacked in the flank or rear and they were partially or wholly enveloped. In 215 BC the two armies established camps about from each other on a plain probably close to Ibera. For several days both simply sent out skirmishers, declining to deploy their main forces. Finally, both armies marched out in force on the same day and deployed in battle order. The Romans posted their troops in their traditional manner, which probably means the two Roman legions were side by side in the centre of the army, with one Italian allied legion on each side of them. Each legion would have sent its javelin-armed skirmishers out in front and formed up in their usual three lines. The cavalry were divided and placed on each wing. Hasdrubal placed his unarmoured Iberian infantry in the centre of his line, with African heavy infantry on their left and heavy infantry described by Livy as “Poeni” on their right; both the Africans and the Poeni would have fought in a dense phalanx formation. Libyan and Iberian cavalry were positioned on the left wing facing the Roman and Roman-allied Iberian horse, while Numidian light cavalry covered the right wing facing the allied Italian horsemen. The elephants were most probably placed at intervals in front of the infantry. The Balearic slingers and North African light infantry formed a skirmish line in front of the elephants. Engagement Livy is unclear or silent on many details of the battle. For example, the effect, if any, of the elephants is not mentioned. At the Battle of Tunis in 255 BC, during the First Punic War, a line of Carthaginian elephants caused chaos among 13,000 Roman legionaries. In that case there were 100 elephants, not 20 or so; perhaps there were too few elephants at Ibera to strike sufficient terror into the legionaries to disrupt their formation. However the elephants