The Battle of Lake Trasimene (June 24, 217 BCE) was a Roman defeat in the Second Punic War between the Carthaginians under Hannibal and the Romans under the consul Gaius Flaminius. Hannibal ordered his forces into the forested hills bordering Lake Trasimene (or, Trasimeno), and waited in ambush for the Roman forces to come by. When the Romans had become fully within the bounds of the Carthaginian forces, the Carthaginians attacked. The Romans were unable to get into their typical battle-formation and were forced to fight unprepared. Many were driven into the Lake. Of the 25,000 or so Roman soldiers an estimated 15,000 were killed.