On March 17, 45 BC, in his last victory, Julius Caesar defeated the Pompeian forces of Titus Labienus and Pompey the Younger at the Battle of Munda." From the article:
"Battle of Munda: Julius Caesar Defeats Republican Forces to End Roman Civil War
Today in Military History: March 17, 45 BC
Today's military history piece highlights one of the ancient world's greatest military leaders. Julius Caesar led Roman armies from Italy to Asia Minor [Turkey], from Egypt to Gaul [France], from Britain to Numidia [Tunisia], winning more victories for Rome than any other general in the history of the Republic. One of his hardest-fought battles was surely this fight, Roman vs. Roman.
Background
After his final conquest of Gaul in about 52 BC, Caesar was hugely popular with the people of Rome but not with the Senate or its leaders. In January of 49 he made the decision to march his veteran army toward Rome to answer charges of treason and insubordination. When he crossed the Rubicon River into central Italy, he set off a civil war. [Readers interested in the crossing of the Rubicon should read my BurnPit post: "Jacta Alea Esto" (Let The Die Be Cast); Julius Caesar Crosses the Rubicon River.]
Caesar's fight with the Senatorial forces took him all over the Mediterranean area. His primary antagonist was Gnaeus Pompeius Magnus, aka Pompey the Great. His military and political successes rivaled Caesar's. They had a power-sharing arrangement from 60 to 53 BC as part of the First Triumvirate with Marcus Licinius Crassus, said to be the richest man in the world at th time. [There was an even more personal bond between Caesar and Pompey, for Pompey's fourth wife was Caesar's daughter Julia.] When she died in childbirth in 54 – and Crassus was killed by the Parthians in 53 – the triumvirate effectively collapsed – though it was scheduled for renewal the next year.
Upon his wife's death, Pompey became a staunch supporter of the Optimates [Best Men], the conservative and socially traditional faction of the Senate, as opposed to those who supported Caesar, the Populares [Populists]. Pompey became the champion of the Optimates, due to his extensive, highly successful military career. [He had celebrated a triumph – the Roman equivalent of a ticker-tape parade down Broadway – when he was 24.] The two men fought over the 20 months from Caesar's crossing of the Rubicon, with Pompey losing the battle of Pharsalus in August of 49. The defeated Pompey fled to Egypt, hoping to receive either support or asylum from the ruling Ptolomies, descendents of one of Alexander the Great's generals. However, Pompey was assassinated by some of his own men – with the help of some strategically placed Egyptian gold for the desired result.
However, the Roman Civil War (sometimes called Caesar's Civil War) did not end with the death of Pompey the Great. He had a son named Gnaeus Pompeius (also called Pompey the Younger) who was also a military leader; he avoided capture after Pharsalus, fleeing to Africa to continue the civil war against Caesar and his Populares. Gnaeus and his younger brother Sextus joined Optimate forces gathered there. In February of 46, Caesar's forces defeated these Optimate forces at the battle of Thapsus. Three Optimate leaders committed suicide rather than surrender to Caesar. The Pompey brothers fled Africa, first to the Balearic Islands, eventually landing in Hispania.
Prelude to the Battle
The Pompey brothers soon took charge of the anti-Populares forces in Hispania. Over the course of several months they were joined by other Optimates units that survived Thapsus. One of those units was a large, veteran contingent of Gallo-Germanic cavalry commanded by Titus Labienus. Titus had been a trusted lieutenant of Caesar's during the conquest of Gaul. However, after Caesar crossed the Rubicon, Titus broke off his association with the conquerer of Gaul and joined the Optimates against his former commander.
Other opponents of the Populares joined Pompey's forces. One unusual source of recruitment were Roman army veterans who had served under Pompey the Great, surrendered to Caesar, then were given land in Hispania to start a new life, after renouncing their former ties with the Optimates. When Pompey the Younger began raising new legions to confront Caesar, large numbers of these veteran legionaries foreswore their oaths and joined the Optimate faction once more.
In late 46, the forces under the Pompey brothers and Labienus began attacking major Roman cities and colony settlements. They captured nearly all of the province of Hispania Ulterior. Caesar's commanders in the area decided to avoid meeting the Optimate forces in battle, hurriedly sent a request for assistance to Caesar, who was now back in Rome.
Forced to move from Rome to Hispania to deal with the Pompey brothers, Caesar covered the 1,500 miles from Rome to Obulco in less than a month, arriving in early December. Although the Optimate forces outnumbered Caesar's army, Labienus recommended that the Pompey's avoid open battle. This forced Caesar to wage a winter campaign, at the same time as his forces were foraging for food and shelter. The Populares forces won some victories, and finally by mid-March had forced the Pompeys to bring their legions out in the open and offer battle to Caesar.
Caesarian Army
Caesar's army consisted of eight legions, and about 8000 cavalry, for a total of about 40,000 men. The majority of the cavalry were commanded by his ally, King Bogud of Mauritania (in North Africa). Caesar had brought two trusted veteran legions from Italy: the Tenth Equestris – which had followed him throughout the conquest of Gaul – and the Fifth Alaudae. Other newer legions, including the Third Gallica [this cognomen probably indicates that its members were recruited in Gaul] and Sixth Ferrata, were recruited in the months before the battle. But in the main he was forced to rely on recruits already present in Hispania.
Pompeian Army
Pompey the Younger had at his command thirteen legions, 6000 light infantryman – possibly local Hispanic tribesmen – and about 6000 horsemen, for a total of about 70,000 men. Pompey had avoided battle for several months. However, he had received reports that many of his soldiers were planning on defecting to the Populares side, thereby forcing him to confront Caesar's army.
Battle of Munda
From the beginning, Caesar was fighting with several disadvantages. First, his army was outnumbered nearly two-to-one by Pompey the Younger's force. Second, Gnaeus Pompey had arrayed his army on a hill, taking advantage of the terrain. There was also a stream at the base of the hill, which would usually serve to disrupt an enemy army charging forward.
We do not have any particulars of how either army set up, but we can be certain that both forces set their formations with right and left flanks and a center. Considering the number of men involved, it would seem logical to assume each wing comprised at least two legions each. Also, each army's wings were likely protected by cavalry. These horsemen were used for either: a) softening up the enemy formations, b) outflanking the enemy, or c) after the battle was finished, the cavalry usually pursued and slaughtered the disordered, routing enemy. [Caesar's Mauritainian cavalry would play a pivotal role in the battle.]
The fighting started in the mid- to late-morning. Both sides understood that this battle would be the final fight of the civil war. There was fighting all along the battle line, no quarter offered, none given. Following one of the primary maxims of Roman strategy, Caesar placed his most experienced troops of the Tenth Legion on his right. The Tenth fought with fanatical devotion for their general. At some point during the battle, Caesar joined the ranks of his favorite soldiers and fought in the front line. The Optimate enemy fought equally hard, but the battle dragged into the afternoon, with neither side gaining an advantage.
Finally, the Pompeian left flank was reeling under the hammer blows of Caesar's Tenth Legion. Hoping to relieve the pressure, Pompey ordered a legion from his right flank transferred to his left. As these troops left the battle line and marched to the relief of their comrades, Caesar's cavalry launched a decisive attack which turned the course of the battle. King Bogud of Mauritania ordered a portion of his horsemen to attack the Pompeian right flank, while others charged the enemy camp in the rear of the battlefield.
Titus Labienus, Pompey's cavalry commander, ordered his Gallic and German horsemen to leave the battle line and attack the rampaging Mauritanians. Labienus's move was misinterpreted by the Pompeian army. Thinking their mounted comrades were leaving the battle, nearly the entire Optimate army lost heart, threw down their weapons, and routed from the field. After eight hours of close-up, brutal combat, the Caesarian army was victorious and the Roman civil war was ended.
Aftermath
At the end of the battle there were about 30,000 Pompeians dead on the field, most of whom were killed in the rout and pursuit; losses on Caesar's side were much lighter, only about 1,000. All thirteen standards of the Pompeian legions were captured, a sign of complete disbandment. Titus Labienus died on the field and was granted a burial by Caesar, while Gnaeus and Sextus Pompeius managed to escape from the battlefield.
Footnote #1: About one month after his defeat, Gnaeus was captured and executed. His brother Sextus survived to initiate another rebellion on Sicily, where he was finally defeated and executed in Asia in 35 BC by Mark Antony, ten years after Munda.
Footnote #2: After the battle, Caesar wrote in his Commentary on the Spanish War, he had fought many times for victory, but at Munda he had to fight for his life.
Footnote #3: Julius Caesar survived his greatest battle by only a year, falling victim to assassins on March 15, 44 BC. In one of history's great ironys, he was killed in the Senate chamber, his body lying in pool of blood at the foot of a statue of Pompey the Great. An autopsy performed afterwards (likely the first in history) revealed that Caesar sustained 23 stab wounds and died from a massive loss of blood."