The Roman army suffered a heavy defeat at the Battle of Cannae

The battle of Cannae was a battle fought between the troops of Rome and Carthage during the Second Punic War in the ancient hamlet of Cannae in southern Apulia (modern Puglia), southeast Italy. It which took place on August 2, 216 BC, is considered to be the most well-known engagement of the Second Punic War. The Roman army suffered a heavy defeat at the Battle of Cannae.

The greater Roman Republic force commanded by consuls Lucius Aemilius Paullus and Gaius Terentius Varro was defeated in the conflict by the army of Carthage, led by the renowned commander Hannibal Barca. The Roman army was attacked by Hannibal, who adopted the double-envelopment strategy, encircling the majority of them before executing them. With a force of around 40,000 soldiers and 10,000 cavalries, Hannibal was the first to reach the scene of the fight. The principal water supply in the region, the Aufidus (now Ofanto) River, was given under his army's control. That put more pressure on the Romans, who would struggle in the early August heat to quench the thirst of their larger army. The hot libeccio wind drove dust and grit into the Romans' eyes as a result of Hannibal positioning his lines facing north, forcing them to face largely south, a disadvantage that according to ancient authors cannot be disregarded. Hannibal also limited the eight Roman legions to a small valley that was bordered by a river.

The Carthaginians are thought to have slain at least 40,000 Romans in a single day accounting for more than 80% of the Roman force. Due to this, the conflict ranks among the deadliest single days of combat in history. Therefore, the Battle of Cannae is regarded as both one of the worst Roman army defeats in history and one of the finest tactical wins in military history.