at Arretium and one on the Adriatic coast; they would be able to block Hannibal's possible advance into central Italy and were positioned to move north to operate in Cisalpine Gaul. In early spring 217BC the Carthaginians crossed the Apennines unopposed, taking a difficult but unguarded route. Hannibal attempted to draw the main Roman army under Gaius Flaminius into a pitched battle by devastating the area they had been sent to protect provoking Flaminius into a hasty pursuit. Hannibal set an ambush and in the battle of Lake Trasimene completely defeated the Roman army, killing 15,000 Romans, including Flaminius, and taking 10,000 prisoners. A cavalry force of 4,000 from the other Roman army was also defeated at the Battle of Umbrian Lake and annihilated. The prisoners were badly treated if they were Romans; captured Latin allies were well treated by the Carthaginians and many were freed and sent back to their cities, in the expectation they would speak well of Carthaginian martial prowess and of their treatment. Hannibal hoped some of these allies could be persuaded to defect. The Carthaginians continued their march through Etruria, then Umbria, to the Adriatic coast, then turned south into Apulia, hoping to win over some of the ethnic Greek and Italic cities of southern Italy. News of the defeat again caused a panic in Rome. Quintus Fabius Maximus was elected dictator by the Roman Assembly and adopted the "Fabian strategy" of avoiding pitched battles, relying instead on low-level harassment to wear the invader down, until Rome could rebuild its military strength. Hannibal was left largely free to ravage Apulia for the next year. Fabius was unpopular at this period with parts of the Roman army, public and the senate, for avoiding battle while Italy was being devastated by the enemy: there was awareness that his tactics would not lead to a quick end to the war. Hannibal marched through the richest and most fertile provinces of Italy, hoping the devastation would draw Fabius into battle, but Fabius refused. The Roman populace derided Fabius as "the Delayer" (in Latin, ) and in 216 BC elected new consuls: Gaius Terentius Varro, who advocated pursuing a more aggressive war strategy, and Lucius Aemilius Paullus, who advocated a strategy somewhere between Fabius's and that suggested by Varro. In the spring of 216 BC Hannibal seized the large supply depot at Cannae on the Apulian plain. The Roman Senate