Norman conquest of southern Italy Ofanto near Cannae, the site of Hannibal's victory over the Romans in 216 BC, and the Battle of Cannae was a decisive Byzantine victory; Amatus wrote that only ten Normans survived from a contingent of 250. After the battle, Ranulf Drengot (one of the Norman survivors) was elected leader of their company. Boioannes protected his gains by building a fortress at the Apennine pass, guarding the entrance to the Apulian plain. In 1019 Troia (as the fortress was known) was garrisoned by Boioannes' Norman troops, an indication of Norman willingness to fight on either side. With Norman mercenaries on both
Socii to raise a double-strength army of four legions and four "alae" e.g. at the Battle of Cannae in 216 BC, where each Consul commanded an army of about 40,000 men. Polybius states that the Romans and their allies could draw on a grand total of 770,000 men fit to bear arms (of which 70,000 met the property requirement for cavalry) in 225 BC, shortly before the start of the Second Punic War. The Romans reportedly asked their allies for an urgent register of all "men fit to bear arms" for a "tumultus Gallicus". Polybius' subtotals, however, are garbled, as he