At the Battle of Munda, which took place on 17 March 45 BC, republican opponents to Caesar were defeated for good. What followed was a new era in the history of ancient Rome.
But the encounter was characterised by uncertainty, with one army nervous despite its numerical and positional advantage, and the other forced to fight uphill with 30,000 fewer men. Both sides knew that the outcome would be transformational for the fate of the Roman Republic.
Pompeian last stand
The loss of the Battle of Pharsalus in central Greece three years earlier, and the subsequent assassination of statesman Pompey the Great, had left the Optimate (republican) forces on shaky ground during Caesar’s Civil War. After their army was destroyed at the Battle of Thapsus by the forces of Julius Caesar in modern Tunisia, they had been forced to operate solely in Hispania, modern day Spain.
Though they had suffered setback after setback, Pompey’s sons Gnaeus Pompeius and Sextus set to building a new army in the region. They weren’t alone. Among their ranks was a man called Titus Labienus. Although once a favoured general of Caesar during the Gallic campaign, Labienus had refused to march on Rome with his former commander and had sided instead with the Optimates. In 46 BC, two of Caesar’s legions, comprised largely of former Pompeian soldiers, defected back to the Optimate side and joined with what remained of Pompey’s army.
Optimate resurgence in Spain
The army began by expelling Caesar’s proconsul in the region. This allowed for exploiting Hispania‘s resources so that the Optimates could raise a third legion. With these legions, Labienus, Sextus, and Gnaeus Pompeius marched west on Hispania Ulterior, and succeeded in capturing almost all of the settlements in the wealthy province. Quintus Pedius and Quintus Fabius Maximus, Caesar’s generals in the area, dared not to meet the Optimate forces on the battlefield. Instead, they camped in Oculbo, calling to Caesar for assistance.
Caesar receives word
At the time, Caesar was in Rome, resting victorious following his defeat of Pompey. But as soon as news of the events in Hispania reached Caesar, his focus swiftly changed. He marched with haste to Oculbo, arriving there in just under a month. On his arrival, he wrote a poem named Iter (The Journey), of which only a fragment survives. That Caesar could compose poetry immediately after such a trek speaks to his cool-headedness, which would serve him well in the forthcoming battle.
Caesar had arrived in early December. The Pompeian commanders steered clear of open battle and instead focused on ensuring Caesar’s army would have to hunt for food and shelter as the winter set in. They were well aware that despite their larger numbers, an open battle would benefit Caesar, and they were eager to avoid that outcome.
Caesar makes his move
Caesar struck quickly to force their hand. A siege of Ategua, near modern Córdoba, resulted in defections to his camp and a blow to Optimate morale. Another fight resulted in further defections. Rather than watch their army dwindle, the Optimate commanders decided to give Caesar the battle he sought.
Even in a weakened position, Caesar was expert in manipulating his opponents.
The Battle of Munda
The Optimate forces totalled 70,000 men, while Caesar’s numbered 40,000. There were still dangers: an open battle suited Caesar more than it did Gnaeus Pompeius, and sections of the Optimates’ men were restless and on the verge of defection.
To counter these disadvantages, Pompey the Younger sought to make the most use of the surrounding landscape. He positioned his army at the top of a hill which held a stream at its base, providing them a good defensive position.
Both sides knew that this would be the decisive battle of the civil war. For the Pompeian force, it was win or die: those that had previously deserted Caesar knew that he would not grant them clemency a second time.
Fearful of attacking uphill, Caesar’s legions were also uncharacteristically timid. Knowing that defeat on this battlefield meant the eradication of every previous victory he had fought for, Caesar remarked that whilst in other battles he fought for victory; at Munda he had fought for his life.
Taking personal control of his favourite legion, the Tenth, he seized a shield from one of his cowering soldiers, ripped his own helmet off, and roared: “this will be the end of my life, and of your military service” (Appian, Civil Wars II. 104), before racing towards the enemy, leading his men personally in a move that could have come from Alexander the Great himself.
The critical moment
The subsequent fighting lasted more than eight hours, with both sides trapped in a brutal melee. When Caesar ordered his right wing to focus on the Optimates’ left wing, the Optimates duly responded by diverting a legion from their right wing.
Caesar’s cavalry, until now further behind the main body of the army, then emerged. They drove into the Pompeian’s right wing with great force. They had tricked their Pompeian foes and manipulated them into weakening their own flank.
Caesar’s strategy was not revelatory, but his ability to influence battle and exploit available opportunities testified to his standing as a victorious general and Imperator.
His decisive action turned the course of the battle. Caesar cemented his advantage by charging the enemy’s camp. As Labienus diverted the Pompeian cavalry to protect the camp, the remaining Pompeian troops made a huge mistake. They interpreted Labienus’ diversion as a retreat, and fled in terror, desperately seeking refuge within Munda itself. Few were successful.
30,000 Pompeians were killed in the battle, while Caesar’s army had lost just one thirtieth of its troops.
All who hadn’t fled lay strewn across the land. Titus Labienus, once so significant to Caesar’s success, died a traitor. Every standard of the Optimate legions was captured by Caesar’s army, a symbolic defeat which matched the literal defeat they had suffered.
Gnaeus Pompeius and his brother Sextus managed to escape, but any hope for the republican cause was dead. The former would be executed just a month later, whilst the latter would manage to survive a further ten years, outliving Caesar but as an exile in fear for his life.
Though Sextus lived, he was no threat to Caesar. At home, Caesar was presented with a triumph in celebration. This, however, proved unpopular with the Roman people. Plutarch described in his Life of Caesar how “he had not defeated foreign generals, or barbarian kings, but had destroyed the children and family of one of the greatest men of Rome”.
Caesar’s celebrations seemed, at best, in poor taste. Pompey had been a beloved military and political leader to the people. Even though his popularity had waned in the years before his death, the total defeat of his cause – and family – left a bitter taste. All the same, in the year following the battle Caesar was made Dictator Perpetuo – Dictator for Life.
The Roman Republic was dead. The Battle of Munda represented the utter defeat of republicanism in Rome, and ushered in a new era: that of the Roman Empire.