Battle of Cannae shaping the military structure and tactical organization of the Roman Republican army. At Cannae, the Roman infantry assumed a formation similar to the Greek phalanx. This left them vulnerable to Hannibal's tactic of double envelopment since their inability to maneuver independently from the mass of the army made it impossible for them to counter the strategic encirclement used by the Carthaginian cavalry. The laws of the Roman state requiring command to alternate between the two consuls restricted strategic consistency. In the years following Cannae, striking reforms were introduced to address these deficiencies. First, the Romans "articulated the phalanx, then divided
Gelo, son of Hiero II title of king. Livy asserts that, after the huge defeat suffered by the Romans at Cannae, Gelo was preparing to abandon the alliance of Rome for that of Carthage. According to this account, he began making friendly overtures to the cities allied to Rome and might have convinced the entire island of Sicily to defect to the Carthaginian side, had he not died later in the year of 216 BC. However, this seems quite at variance with the statement of Polybius of his uniform submission to his father's views and may very likely deserve as little credit as Livy's insinuation