Second Punic War in 217. Moving to southern Italy in 216, Hannibal at Cannae annihilated the largest army the Romans had ever assembled. After the death or imprisonment of 130,000 Roman troops in two years, 40% of Rome's Italian allies defected to Carthage, giving her control over most of southern Italy. Macedon and Syracuse joined the Carthaginian side after Cannae and the conflict spread to Greece and Sicily. From 215–210 the Carthaginian army and navy launched repeated amphibious assaults to capture Roman Sicily and Sardinia but were ultimately repulsed. Against Hannibal's skill on the battlefield, the Romans adopted the Fabian strategy – the
Titus Manlius Torquatus (consul 235 BC) to cross the Po river, then defeated the Boii there. The Celts lost 23,000 men and 5,000 of them were captured, but the consuls had to retreat because of poor weather and decease among their troops. In 216 BC, as one of the most senior senators then living, he successfully opposed the ransoming of the Romans taken prisoner at the Battle of Cannae, on the grounds that they had made no effort to break out of the Carthaginian lines. In 215 BC he was sent to Sardinia, after the illness of Quintus Mucius Scaevola and defeated a Carthaginian attempt under