The Battle of Thapsus, February 6, 46 BC.

At the Battle of Thapsus, which took place on February 6, 46 BC near Thapsus in modern Tunisia, Julius Caesar’s army delivered the final blow against supporters of Pompey the Great.

Background

In 49 BC, the Roman Republic plunged into its final civil war as Julius Caesar defied senatorial orders to disband his army following the Gaul campaign and advanced towards Rome. The Optimates, lacking an organised army, sought refuge in Greece under Pompey’s leadership but were eventually defeated by Caesar at Pharsalus. After Pompey's assassination, the surviving Optimates regrouped in the African provinces of Mauretania. Key leaders included Marcus Cato (the younger) and Caecilius Metellus Scipio, along with prominent nobles like Titus Labienus, Publius Attius Varus, Lucius Afranius, and Pompey's sons, Sextus and Gnaeus Pompeius. Following a brief return to Rome and the pacification of the Eastern provinces, Caesar pursued his adversaries in Africa.

In December 49 BC, Caesar reached the coast near Hadrumetum, but a storm scattered his transports, leaving him with limited forces. Hadrumetum, defended by an Optimate garrison under Gaius Considius Longus, resisted negotiation, and probing attacks revealed the city's impregnability. Harassed by Numidian light cavalry, Caesar strategically marched to Ruspina, fortifying it as he awaited reinforcements.

As Optimates gathered near Hadrumetum, Caesar, reinforced and successful in skirmishes, launched an offensive. He defeated Optimate cavalry near Ruspina, prompting them to seek support from King Juba I of Numidia. He then marched on Uzitta to provoke a battle, but Scipio hesitated. Attempts to lure Caesar from his camp failed, and his forces strengthened with additional legions. This prompted some Optimates to defect. Despite this, the Optimates refused to engage on Caesar's terms and retreated to Ruspina. Further reinforcements and supply challenges shaped Caesar's strategy, with his fleet blockading Hadrumetum and Thapsus. In the meanwhile, the Optimates shadowed Caesar, harassing his army during foraging operations in the areas around Aggar and Zeta.

The Battle

In early February, Caesar besieged Thapsus with a double circumvallation and a naval blockade, limiting landward access to two approaches. By fortifying the southern route, he compelled the Optimates, led by Metellus Scipio, to choose between attacking the fortifications or navigating through the eastern approach. Opting for the latter, Scipio stationed Afranius against the fortifications and directed Juba and Labienus to camp south of the marshes with Numidian cavalry. Caesar, aware of Optimates' fatigue, strategically positioned his well-rested army to face them.

The conflict commenced with a trumpeter's signal, prompting Caesar to order a general advance. He directed his archers on the right to target the opposing elephants, inducing panic among them. The left flank also confronted a charge from elephants, but Caesar's light infantry and cavalry skillfully diverted them. After repelling the elephants, Caesar outmanoeuvred Scipio's forces, dismantling the camp and compelling a retreat. Thapsus's garrison sallied out, attempting to attack Caesar's siege works, but they were repelled by the legions left for the siege. These legions then prepared to attack the Numidians, but before they could act, Juba's allied troops deserted, sealing the battle's outcome. Upon reaching the Optimates' camp, Caesar discovered it already stormed. 

Around ten thousand enemies were killed, and despite Caesar's orders to spare them, his soldiers, in a frenzy, disregarded the directive. Some sources suggest that he had an epileptic seizure just before ordering the advance, which contributed to confusion and disobedience during the battle.

Aftermath

After their defeat at the Battle of Thapsus, Scipio, Labienus, Juba, Afranius, and Petreius managed to escape. Labienus sought refuge with Gnaeus Pompeius in Iberia, while Afranius and Faustus Cornelius Sulla, Sulla's surviving son, engaged in pillaging eastern Mauretania. Publius Sittius, a Roman mercenary commander allied with Caesar, apprehended Afranius and Sulla, leading to their execution a few days later. Juba and Petreius, anticipating Sittius's approach, opted for suicide.

Following his victory, Caesar proceeded to Utica, where Cato was stationed. However, upon learning of his allies' defeat, Cato committed suicide. Meanwhile, Scipio attempted to escape to Roman Hispania but faced adversity due to bad weather, forcing a return to the African coast. There, caught by Sittius and his fleet, Scipio took his own life by stabbing himself with his sword.

The Battle of Thapsus marked the precursor to peace in Africa, with Caesar withdrawing and returning to Rome on July 25 of the same year. However, opposition persisted, as Titus Labienus, the sons of Pompey, Varus, and others assembled a new army in Baetica in Hispania Ulterior. The civil war endured, leading to the upcoming Battle of Munda. Notably, the Battle of Thapsus is recognized as the final large-scale use of war elephants in the West.